Plenty of 2-up friendly bikes, from V-Stroms and Versyseses to R1200GSs and RTs, and a Super Tenere and a Multistrada even -- but they can't be taken off-road, at least not without invalidating your rental contract.
The only other moto rental shop in SF is Eagle Rider, but they mostly rent Harleys©®™. I think there's one down on the Peninsula and another way out in Concord.
There are lots of great day rides available in the area. If you're based in SF, you have 3 choices:
south (92/35/Alice's/84/Pescadero/9/236 etc)
north (Lucas Valley Rd/Point Reyes/Marshall/Cazadero and/or Highway 1 all the way to Stewarts Point/Skaggs Springs if you're feeling really adventurous)
and east (Mt Hamilton/Mines Rd/The Junction/Vasco/Marsh Creek or Morgan Territory/ Mt Diablo/Palomares)
Late April can still be iffy, weather-wise, but odds are it'll be very nice.
I don't do that newfangled GPS track schtuff, but I'm sure someone can help you out.
Oh, and happy anniversary.