I live about 15-20 minutes outside of the city, but I still say I'm from Pittsburgh... Nobody is going to know what I'm talking about if I say I'm from my town.
And on top of that, even people FROM Pittsburgh have sometimes never heard of my town. So I still just have to say "Okay, uh... Have you ever heard of *nearby rich town that I could never afford to live in*? Yeah, it's across the river from there."
So basically, I'm a poseur no matter what.