On the corner of State and Grand in downtown Chicago is Rock Bottom Brewery, but for those inclined toward truncation, you simply can refer to it as RB Grille:

Does this branding truncation work for you? In my opinion too much meaning is lost. It’s also curious to me that the RB Grille “story” doesn’t even reference “Rock Bottom” — any of our Windy City readers know why?

Last, I wonder if it works for Mr. Brennan from Madison, Mississippi? — the owner of the only mark containing “RB” that is presently federally registered for restaurant services.