None of my coworkers at the place I work part-time are Greek, but we do get a lot of customers who are.
There have been some kind of awkward recognitions - for example, once a guy in a fraternity that I had a class with came in while I was working, and he was like "...wait... you work HERE??" I guess I can sort of understand his surprise, since there aren't a whole lot of girls who work at video game stores in the first place, let alone Greek girls who work at them.
None of my coworkers at the other place I've worked were Greek either, but that's a little more understandable as Greek life and the student paper on my campus have a rather iffy relationship.