I seem to recall San Francisco's water is not high in dissolved minerals. You can find out. Go to your water utility's Web page and look for their annual water quality report.
If you have a winter with a good amount of rain most other orchids will struggle in the cold and wet.
__________________ May the bridges I've burned light my way.
I wouldn't worry about water quality even if you aren't in the city - surrounding areas have a range of levels of solids in the water. But these are not sensitive. Mine get city water and they are fine. When you say "San Francisco Bay area" that covers a huge range of microclimates, so you do need to be a bit more specific with regard to what you experience in terms of temperature ranges.