I have the Southwest card. If they still do the companion pass you and your wife should each get a card when it's 50,000 bonus points.
I don't think getting cards for each of us (separate rapid rewards accounts) would work because all of the 110,000 points have to be on one account to get the companion pass.
We mainly fly Southwest but cannot always. Because of that, I like that you can get 2x points on all dining and travel purchases with Chase Sapphire Preferred and the points can be transferred to Southwest at 1:1. Southwest RR card you only get 2x points on Southwest purchases.
I'm leaning towards the Chase card, but the sticking point is that with Southwest's card you get an annual bonus of 6,000 points. With Chase Sapphire Preferred you get no annual bonus. So you'd have to spend enough on dining and travel (uber, tolls, hotels, flights, mass-transit) to make up for the annual free points given on the Southwest card.