Originally Posted by
mnbp
Your Amex card is associated with your SkyMiles number/account. The benefits are given no matter what form of payment is used to purchase your ticket - the benefits accrue to you through the SkyMiles number associated with your reservation.
You can add your SkyMiles number to an existing reservation at DL.com if you didn't do this when the ticket is purchased. You can double check on DL.com to verify that your correct SkyMiles number is associated with your existing reservation. I wouldn't wait until flight check-in to do this.
No, SOME benefits such as baggage allowance are extended while others are not.
javabytes brought up a fine example: double miles will not be awarded. One of the reasons why I cancelled the card was the subpar mileage yield when using the card outside of DL playground (though even some DL-internal sales such as on-board duty free will not yield double miles).
I honestly don't know who really gets a monetary benefit out of that card: the bags. Unless you're travelling only like once a year with your whole family having a bag to check, nothing is really worth the fee. After 2/3 trips, you'll be FO anyway.
Originally Posted by
javabytes
One question would be double miles for Delta purchases. Don't know if you get this when booking DL flights through third party sites; happy to be corrected though.