I think that locale and food are probably the only thing that would matter more with a restaurant than other businesses. Were I working on a restaurant I would check out every restaurant nearby and make sure that the type won’t by confused with competitors. It’s probably also good to make sure that the menu type does not clash with the food; I often eat at a place that serves a mix of flavorful American and French dishes and has a menu set in Helvetica, which just does not connect at all.

Are you speaking of designing a logo for a restaurant? An advertisement? A menu?

James has given you good advice, I’d just like to add if you are designing/working on the menu - find out what the age group will be frequenting the restaurant. Keep a style in mind for what their eyes can read... Also, how is the lighting at the restaurant? Older folks need larger type... etc. etc. etc.