And to state (repeat) the obvious: when paying for a ticket with wallet credit, one can force a small portion of the fare (say, $1) to be paid with the AS Visa to activate the bag fee waiver by doing the three-step-tango as follows:

Scenario: Wallet credit of $500, want to buy ticket for $400 and get bag fee waiver.

1. book dummy ticket for $101 with wallet credit, resulting in a remaining wallet balance of $399
2. book actual ticket for $400, paying with $399 wallet credit and remaining cost of $1 on AS Visa
3. cancel dummy ticket, resulting in new wallet balance of $101.

(wouldn't it be nice if AS, like UA, would simply ask how much wallet credit one wants to use?)