So getting a good GPA in a non-top school is still acceptable?
No. To have any shot in management consulting, you need to attend a target school. The target schools include top schools, but not necessarily all are Ivy League schools. Some (a very small number mentioned above) top public schools are included.
If you attend a non-target, even if it's a good school (let's say Penn State), you have virtually no chance of getting hired at a management consulting firm unless you're a Rhodes Scholar.
Accounting firms are a different beast because they hire more people, so they will go to non-top schools. However, the salaries and work are very different.