Provides the mayor’s the new spouse, who’s simply 20, come sipping? 1 from step three SEPT 6 – Starting evening on San francisco bay area Symphony. Vignettes of various trend regarding San Francisco’s better-heeled. Brittanie Mountz and Mayor Gavin Newsom. By the JOHN LEE/Unique Towards the CHRONICLE Ran towards the: 09-21-2006 Symphony board regarding governors…