~320,000 citizens of Filipino decent in the Bay according to the 2000 census, so yes it's a big population, though I know that number doesn't reflect Filipino as a person's primary language, but still it's a good indicator.

https://en.wikipedia.org/wiki/Demographics_of_Filipino_Ameri...

According to census estimates, the most spoken languages in SF besides English are: Chinese (152k), Spanish (90k), and Filipino (24k): https://sfgov.org/oceia/language-diversity-data

Yes there is a large (aging) pinoy population in San Francisco and Daly City. Do you think they just pick languages for fun?

yes