I guess, thanks, but it looks like exactly the same problem: It sets affordability requirements as low as 5%. See: 65913.3(b)(4)
The Governor’s budget trailer bill says that if a developer sets aside a certain fraction of the units for inclusionary housing and the proposal complies with the local zoning code, then the locality must approve it deterministically and quickly. This does not prevent a local government from setting a higher inclusionary requirement in their zoning code; it would remain 12% in San Francisco (or higher if Proposition C of June 2016 passes). The inclusionary fraction in the bill is just the threshold at which the other provisions begin to apply.
By the way, the Legislative Analyst’s Office has released an endorsement[1] of the bill which provides background, justification, and proposed improvements.
But speaking of the affordable housing bonus, Tim Redmond’s specific concerns seem to be that height limits, setbacks, and backyard requirements may be waived, not that there would be any reduction in affordable housing. But I agree that the affordable housing bonus law is somewhat open-ended so who knows what concession a developer might request.
[1]: https://leginfo.legislature.ca.gov/faces/billTextClient.xhtm...
[2]: http://web1a.esd.dof.ca.gov/Documents/bcp/1617/FY1617_ORG224...