If one were optimizing distance to Levi I think SJC would be the choice. As it were MRY is only 35 minutes further driving to Levi than SFO. Seems worth it for a 6K and 9.5K redemption, plus there is plenty to see/do in Monterey County.
It's at least an hour farther from Monterrey v. SFO to the Stadium, FYI