While SFO is not home, I go through it a lot.
Maybe my bad luck, but every flight I have flown to SFO last month (around 10, mostly AS and UA) has been held in a holding pattern, a couple of go arounds, leading to some dicey onward transfers - I won't call it connections since some of them were mileage runs on separate tickets.
There was even one-time where I observed SFO using 28R for all takeoffs and landings.
With regards to OP's situation, 1.5 hrs generally sufficient, even with some delays. All things being equal, if there are holding patterns and go arounds, it would impact both OP's aircraft from Canada and the inbound aircraft of the connecting flight. That said, the connecting flight is a long haul, so the gap time between flights are usually longer, which could play a factor. Anyway, I still think generally no issues with 1.5 hrs assuming the flight from Canada is on time; even a slight delay should still afford OP more than enough time for the connection.