I notice the wiki mentions that Citi Card can be paid over the phone with the UFB Direct debit (checking?) card. When making this payment by phone, does it register the transaction as POS/Purchase, and that's why rewards the AAdvantage miles for UFB? I'm very surprised to learn that one could earn miles on payment for a bill, but I'm exceptionally new here and trying to wrap my head around this whole thing.

If someone could kindly provide any insight they may have it would be much appreciated!