You are absolutely correct about this. It varies from school to school, of course (since every honors program is different), but I think most of the benefits of an honors program are intangible. The honors designation itself doesn’t carry much weight. If access to these benefits will dramatically improve your post-graduation prospects, then the honors program might be worth it. But, again, linguistics isn’t my field and I’m not familiar with the honors program at your school. The math double major still sounds like the most universally sound option to me for the doors it will open.