Originally Posted by
UAPremExecflyer
Air Canada flies from the International Terminal at SFO. AC contracts to use the Air France lounge as nnn notes above from personal experience.
You will have no access to a oneworld lounge with a *A BP.
Yes, I think that SFO does the typical airline grouping: keep the alliances together airside to the extent possible. International-G is Star Alliance. I-A is One World and Sky Team.
If you find yourself in an exceptional situation, such as the Air Canada flight departing out of I-A mentioned above, inquire with check-in and gate agents about lounge access via a contractual arrangement your airline has with another.