Unless you need some additional EQMs to reach the next elite level that you wouldn't reach otherwise, and you can take advantage of, and highly value, those additional benefits that higher status brings, I'd think it makes more sense to put rent payments on the Bilt card. As eponymous_coward has pointed out, you'd be paying 1.5 cpm, not 1 cpm. In fact, I'd argue that you'd be paying more than 1.5 cpm, because 1 Bilt point is currently worth more than 1 AS mile (due to the optionality embedded within a transferrable currency like Bilt and other Bilt's valuable transfer partners like Hyatt). An AS mile used to be well worth that price, but not anymore with its recent devaluation.