I am considering changing jobs to a small company, but I don't know if I would get Maternity Leave disability benefits in California. The company only has about full time 20 employees in a 75 mile range, but at least 75 temporary hires. Does this count to be a 50 person firm?

State Disability is not dependent upon how many employees the employer has. It's funded strictly by the SDI deductions from your paycheck.

Also you would be eligible for 6 weeks (in addition to any SDI time off) for bonding in California. Your job is not protected during this time, but you can collect that. More info is available at http://www.paidfamilyleave.org/.

Sounds like you would not be eligible for FMLA (both CA and Fed) by making the switch to a smaller employer. That is generally unpaid anyway.

The temporary hires probably count. You would be eligible for CFRA and FMLA after you worked there a year (and 1250 hours).