Eh, they expressed gratitude. I don’t really care if it’s to me directly, DW, or both of us. In my mind DW and I are a “family unit”.
As long as I know they said thank you to some portion of the family unit, I’m good.
That said, I understand that others are more sensitive to certain etiquette rules and I can understand where OP is coming from. For my part, thank my spouse and pick up the next one and we’re all good.
I feel the same, it wouldn’t bother me a bit, we are a unit. I also think it’s okay to leave a gathering, and just say goodbye to one spouse if the other isn’t nearby (but I’m also like an Irish goodbye and might not say goodbye to most, lastly because I don’t want to be the one to end a party).
I don’t pick up a tab to be thanked.
I guess I’m somewhat sensitive to the misogyny that the man is in charge of making financial decisions and should be the one thanked. That the man is the griller and should be thanked because it’s the woman’s job to do all the other things when entertaining. That by only thanking the husband, you are marginalizing the wife’s role in their family.
I wonder if my husband has ever thought about inherent bias.
No matter your motives for picking up the check, it’s good manners for the recipient to express gratitude.
Changing the subject a little bit and hope that @conmama is ok with it
I can be sensitive to man jobs and women jobs. Maybe I’m wrong but I wonder if that the annoyance is that @conmama feels marginalized when her husband was thanked while she was in the bathroom. That’s what I would be annoyed by.
I also have a daughter and a daughter in law who are engineers. My daughter, she’s the one who’s mechanically minded, she’s the one who knows how to deal with contractors, it’s what she does for a living.
My mom, sigh! She seems to think that my husband because he’s a man, knows how to do certain things. No, I do those things. But then my mom seems to think that others are there to do her bidding! Maybe that’s not a good example lol!
The world, it’s a changing! I’m tired of these gender stereotypes!
We would say thank you at the moment the other person(s) picked up the check. I guess now that I know a not-present spouse might think it thoughtless might reconsider.
But… to me the bigger thing would be to thank BOTH hosts at the end of the trip. There is a lot of work involved with house guests…with coordination, prep, cooking, sheets etc. Even if there is a gift brought at the beginning of a trip, heartfelt thanks (and perhaps a thank you note later) are nice. LOL - one friend shipped me a box of chococates from her hometown, much more than expected but very sweet, literally
I see where you’re coming from, but with my in-laws my MIL was the handy one who did everything. FIL just wasn’t. My dad was the engineer who did the construction/maintenance stuff, but my mom was in charge of the finances and basically ran the household. My kids were raised where I took care of most things, though I let H deal with contractors. I do it at work. I don’t want to at home, and he is very persistent! (Nice way to saying nag)
So in our family, neither of us have felt like that, though I know the stereotype certainly exists.
This reminds of the Curb Your Enthusiasm scene at https://www.youtube.com/watch?v=2RbNpzasvqw .
I personally prefer some form of splitting the bill. Splitting has its own set of potential issues, but I find it preferable to the alternative of one person/party paying and it being unclear if that person/party expects anything in return (being thanked or you do something to appear grateful, you pay their bill at next meal, you pay for something else in the trip, you let them have their way on other issues because they paid the bill earlier…).
I don’t know if I agree with you. They thanked your husband as he paid the bill. Maybe they thought he would tell you. It’s kinda uncomfortable to rethank someone that comes later. Sure, it would be nice and I would probably do it. Or at least say something like “next time we got the tab” to you.
But damn. At least they thanked your husband. It’s not like they didn’t do it at all.
Honestly I wouldn’t notice who thanked who.
But how would they know? That is the strong cue to hubby to praise you. I clean and my wife cooks. She’s like a chef. Seriously. I help prep. We host large holiday dinners and friend’s. They look forward to coming over. When they praise my wife I joke about bringing it to the table. Lol. As our friends leave they usually thank “both” of us for hosting. I appreciate it but find it annoying sometimes. If we didn’t want you here we wouldn’t of invited you… Lol.
Haha, my husband talks to the contractors. He’s a retired project manager and is much more diplomatic than I am.
At this point it’s actually kind of a joke amongst some friends and family - they know to thank husband, me, and everyone who brought something or helped in another way. They’ve been “trained” 
I have a related question but don’t want to derail this convo. Related post incoming. 
Yep. That is our group. Then we will get an email as Sharon (real name) is in the car thanking us for hosting again on a group chat… It’s like clock work… Lol. Yes. It’s very nice. But to me it’s so unnecessary. It’s like passing someone and asking - How are you doing? Few care. Lol. We invited. So we wanted you to be there. Usually someone is bringing dessert or a side or wine. Unless my wife says not to. They all have been trained to listen to her 
.
Honestly in a million years I wouldn’t think that, but maybe it’s just not how anyone I know operates. I can’t imagine being married and having finances so separated as that their appreciation would be separate.
Laughing here because husband and I share finances 100%. I still thank him when he pays for our dinner. It’s not about the money. It’s just recognition that it’s nice that he takes care of the small but necessary chore.
This. Plus, I can’t imagine picking apart how my friends thank us.
Is your husband always the one who pulls out the credit card? Given that these friends offered profuse thanks and this seems to be a pattern of annoyance with friends in general for you, I’m wondering if your issue is more with the traditional gender roles that you and your husband have taken in your relationship and less with how others are responding to them.
You said you couldn’t imagine picking apart how my friends thank me.
That’s the thing, right? The annoyance.
The friends didn’t thank me.