Hi Robyn!
Good question. I can see how being able to distinguish venues with categories would be super helpful in this case.
The easiest answer is to give the locations unique names. For example, if you have two Starbucks locations, one might be Starbucks on 3rd and the other Starbucks on Main.
Another way to do it might be to create a custom taxonomy (aka category) for venues. Venues themselves are a custom post type (registered as tribe-venues), so you should be able to create a custom taxonomy for it and then could use it like you would post categories–only for venues.
Sorry I don’t have a concrete solution for you here, but does this at least give you some ideas to work with? Please let me know. 🙂
Cheers,
Geoff