For Flights depends on which cards you hold, platform doesn't matter as more or less they are the same
AU Bank currently runs Flat 15% offer in Paytm, Cleartrio and Yatra
Which can be availed once a week, Other than that if you have DCB or Infinia , Smartbuy gives approx 17 % points /cashback. I personally use a combination of AU card , Bank of Baroda and DCB for flight bookings