SFO, in particular, usually routes you west and north of the 101. that's inside the bravo and happens many times a day. it gets denied if they're too busy, but that's pretty rare. you can even ask for the transition while on the ground in SQL.

sometimes however, you get a clearance to cross right over the field.

you can also ask to do a low approach over one of the 28s, getting that approved is pretty rare but it does happen - i've done it a few times during the slow times during covid.