I think just changing "California" to "Bay Area" would be reasonable for now. If the article is correct, zoning is being completely eradicated, but I'm not sure why the poster decided to say it was for all of California.
You could go with something that's more technically correct, if not immediately more clear. This would at least give people the opportunity to google the terms and learn about them themselves.
"Builder's Remedy goes into effect in many California cities tomorrow"