SPG points will transfer to pretty much any airline program at a rate of 1:1 or 20K SPG to 25K other frequent flier program. (creditwalk.ca)
U.S. Bank has several partnerships with other frequent flier programs. (creditcards.com)
Unlike other frequent flier programs which have a zone or distance based award chart, with Southwest, each Rapid Reward point is worth a fixed amount. (pointswithacrew.com)