Shanghai Kelly's is a well-known Steelers bar in Russian Hill. i've never been there during hockey season but i bet they show Pens games.
Giordano Bros in North Beach serves some pretty good Primantis knockoffs. they have Steeler games and Yuengling. think they show Pens playoff games too but i've never been around during a regular season game.
most bars are pretty friendly when it comes to requests to watch out-of-town sports. only time i coudln't catch a break is when my buddy and I wanted to watch the Michigan-Nebraska game concurrently with Game 3 of the World Series. but that's a request that's not going to get honored in any town.
i watched game 7 of the Montréal series in a dive in Santa Clara. i'd just half-assed a law school final and rushed into the bar closest to where my car was parked. was quite surprised to see that they were playing that game. but i think back then everybody was carrying Versus.