AS for sure, unless flexibility is important. As an MVP, she'll get free upgrades which happen quite regularly on the Bay Area flights (I definitely wouldn't categorize MVP upgrades as "rare"). I'm an MVP and I've managed a 100% upgrade rate on flights out of the Bay Area for nearly two years now. If the travel pattern involved frequent transcons or trips to Alaska, upgrades would be much harder to come by. AS also offers more flexibility in airport choices, serving SFO and San Jose in addition to Oakland, whereas Southwest is limited to just Oakland and San Jose. I assume you have your own opinion about the usefulness of SFO compared to OAK and SJC since you've apparently lived here.

Southwest would allow some additional flexibility in changes to flights because there is no change fee and the last minute purchase fare is almost always much better than AS. Southwest allows you to apply the entire value of one ticket to the cost of another if you need to cancel and/or reschedule, and charges no fee for the convenience of doing so. This is a tremendous value to those who fly regularly, because it allows them to book non-refundable travel in advance without worrying about losing those funds if a meeting gets cancelled. If your plans change, you can just cancel the ticket and buy a new one or save the amount for a later puchase. Alaska allows this on some fares, but will charge you $50 for the privilege. Moreover, try and change your outbound flight on Alaska one day before departure and you'll have to buy a full Y fare which is priced much higher than Southwest's full Y. Of course, AS offers free sameday standby on most tickets whereas Southwest does not.

In any event, my choice would be AS but I'm not really a business traveller so the flexibility issue is less important.