Delta Partners fee's when booked with Delta
 

I have been a frequent flyer with Delta. I use the Delta Platinum card to accumulate additional points and no baggage fees. I flew out to Seattle on a Delta flight. While checking in for my return flight...on the Delta site, using my Delta frequent flyer number, I find my return flight is on Alaskan and I will have to pay the baggage fee. Called Delta Customer Service, ...NOTHING... I've had enough. I'm cancelling my card and will use other carriers.

Aw, so sorry to hear that.

I'll save you a future complaint, other airlines do the same with non alliance partners.