By L E Modesitt Jr =) He's also written quite a few scifi that aren't too bad. His Ecolitan series is almost purely a political space opera style on an environmental scale.

And yes, Spider Robinson's main series is set in a bar (with various facelifts as time goes by) that started with the name Callahan's crosstime saloon and bar. He's written other once-off books that are quite good to re-read.