Citibank credit cards can finally be used on Apple Pay! From now until 31 Jul 2018, Citibank credit cardholders can stand to earn up to 8 mpd by using Citibank credit cards on Apple Pay.
Specifically, Citi Prestige and Citi Rewards credit cards will earn you 8 mpd, while the Citi Premiermiles Visa card will earn you 4 mpd.

Note that there is currently no cap on the number of miles you can earn from this promotion. However, you may not stack this promotion with other ongoing Citibank credit card promotions. You should also note that this promotion is also applicable to in-app Apple Pay transactions, in addition to the usual over-the-counter ones.
This is by far the most attractive way to accumulate miles from regular credit card spend, at least until the end of July. So be sure to add your Citibank credit cards on Apple Pay, and tap your way to more miles!
Full terms and conditions can be found here.