I work inside one of the aforementioned financial institutions. When customers approach our counter they are still on the supermarket tile, but we also have an office that is clearly not (you go through a door). I've asked around about this and the answer I was given is "Office is a no go, but because the outside of our teller line is part of the store it is fine." Some of the other in store branches are set up differently, where the entire branch is contained in a basically separate room set out from the rest of the store typically delineated by carpet, or where a gate comes down at closing time, those are a no go for carry altogether.
Just my 2 cents, take it for what it's worth.
If I was allowed, I'd carry at work...