There are plenty of ally/partner organizations. "East Bay For Everyone" is the east bay one, and there are a few budding orgs in silicon valley (http://www.sjyimby.org/). We all work on local issues, and partner on big projects. For instance, I live in SF but I have traveled to mountain view to advocate for the north bayshore development. SFYIMBY is the "mothership", is the most mature and has the most power to drive votes at the state level.