Hi. New member here but lurked forever. I recently booked a flight with a Chase Sappire credit card on a Delta operated and marketed flight, but I also hold an Amex Platinum Skymiles credit card. I am booking a basic economy ticket on an international flight. I am wondering whether I have to use the delta CC to get the free checked bag? Last year, I got the free checked bag but I booked it with Delta. There's a bit of conflicting information on the T&C. In one part, there's no mention of having to use it but on another section it says that it has to be used.

I have reached out to Delta via twitter and customer service and everyone has said yep don't need to use it. Just wanted to follow up here to find out whether anyone has actually done it with success.

Thanks in advance.