I think I've solved this mystery. California doesn't have a "UberPass" discount.

FROM UBER:

An Uber Pass subscription gives you instant access to benefits including savings on rides and Uber Eats orders.

"When riding, you'll get 10% off each UberX, UberXL and Comfort trip and 15% off premium rides, including Black, Premier and SjUV. Additionally, you'll have access to a $0 delivery fee and 5% off Uber Eats orders. A $15 minimum order (not including taxes and fees) applies.

You can purchase an Uber Pass for $24.99/month and use it in cities across the United States (outside of California)."

US Uber Pass

Case closed.