I have both. (Well, I have 3 AS cards and 1 UA card)

AS currently gives 1K booking bonus for each ticket purchased with the AS Visa, plus the $99 companion fare (get the personal signature card, not the business one). Also, most if not all fares price as one ways so you can purchase each direction separately and get another bonus (and only have to deal with one bad direction if you need to change/reissue just one way).

If you are charging that much, you may want to split them up, maybe even between AS, UA and a hotel program, so you can earn free stays for when you redeem your miles.