My Brother lives in the Mission and I get out there a few times a year to go see him. In the smaller bars there, (the mission) there is believe it or not there is a bit of a "jug" band revival scene going on. We hit a place on Valencia st somewhere between 20th and 18th and had a great time, really cool room with hi stage at the back with a upright piano propped up against it. the band (who's name I cant recall) was great; Jug, wash tub bass, arch top guitar, piano, and two black chicks doing killer back up and sometimes lead vocals, 7 or 8 piece band in all, really great! And apparently they play there all the time, sorry the details are sketchy but the Mission is really hip and defiantly worth checking out at night, also you should stop into the 500 club at 17th and Guerrero, my favorite SF bar.
Also take an afternoon and drive around Marin. Your lady will like it because it's very beautiful but you can hit a bunch of spots that have excellent GD significance. The Dead where after all a Marin band, they left SF in the late 60's never to return. Mill Vally, right across the Golden Gate and at the base of Mt. Tam, is where Bobby has lived since the early '70's is a really cool little town and worth checking out. Stinson Beach is where Jerry lived, for a long time, also Micky built the first "Beam"out of a chunk of driftwood from there. Stinson is overrun now with the rich and snobby but still is very pretty and there is a good little grocery right in town to grab some Racer 5 IPA's and a few sandwiches for a nice picnic lunch. Have a great trip, its a great time of year to go.