https://www.americanexpress.com/us/credit-cards/card/platinu…
These are all new to me. However when I tried to register a qualifying airline, the computer said
"None of your benefits require the selection of a qualifying airline."
There are others too, but these are the 2 of most interest to me.
5X MEMBERSHIP REWARDS® POINTS ON ELIGIBLE TRAVEL‡
Get 5X Membership Rewards® points on flights booked directly with airlines or with American Express Travel and 5X points on eligible hotels booked on amextravel.com.‡
$200 AIRLINE FEE CREDIT‡
Enjoy perks while you fly.
Feel free to check your bags or enjoy an in-flight meal on us. Select a qualifying airline and then receive up to $200 a year in statement credits when incidental fees are charged by the airline to your Platinum Card® account. American Express relies on accurate airline transaction data to identify incidental fee purchases. If you do not see a credit for a qualifying incidental purchase on your eligible Card after 4 weeks, simply call the number on the back of your Card. See terms & conditions for more details.‡
T & C's
https://www.americanexpress.com/us/credit-cards/personal-car…
That's the US site.