Personally, I would suggest that the Bank Protection Act (though I'm not sure how heavily one could lean on it) would override any local, county ordinance - the safety and security of my staff and customers come first and I'm not comfortable with the public in our restrooms. Particularly since at most of our banking centers they are out of sight and it's easy to "lose track" of customers (potential threats) until we've closed (or even worse - the next morning).
_________________________
My comments are absolutely no reflection of, nor influenced by, my employer - take them at your own risk.