Thanks for the replies. I'm hearing that a weekly commute is much less common than I thought it was, so it looks like the Companion Pass idea is out.

I was looking for something exactly like that commuter book, but I can't find an airline that has one. I found an article that says SkyWest is partnered with Alaska to do 3x daily SAN-SJC trips, but I couldn't reach SkyWest directly.
http://patch.com/california/santee/a...ego-san-jose-0

The Alaska flights are actually pretty great -- 6:30-8am Monday, 8-9:30pm Friday, $147 round trip ($7.5k/year). I would like to remove the uncertainty of traveling near the holidays though with a fixed rate fare.

American's cheapest AirPass package is $10k, and it doesn't look like they fly direct at good times.

I'll definitely check whether my company gets a corporate discount too.

I also saw this place: https://www.onego.com/
They're an expensive ($1500/mo) subscription flight service that basically gambles on customers flying infrequently enough that they profit. It might be interesting to see a similar commuter travel service.