With the introduction of the ability for American frequent flyers to earn miles and elite status flying JetBlue, and vice versa I’ve gotten several questions about the relationship centering around taking advantage of both programs at once.

The most important thing to understand is that right now you can earn miles and earn credit towards elite status in one program while flying the other airline, but there is not recognition of one program’s elite status when flying the other airline (the way there is between American Airlines and Alaska Airlines). That will come in the future.

• You can’t take advantage of elite benefits from one program while flying the other airline even if you book a codeshare. I am glad to see this reciprocal mileage earning. Until now AAdvantage members could only earn miles and status when booked on codeshares (American Airlines marketed flights operated by JetBlue). I do not like codeshares. However some readers seemed to think that elite benefits would apply to codeshares. They do not.

  If you have Mosaic status you don’t get a checked baggage benefit flying American, if you have AAdvantage status you don’t get elite benefits flying JetBlue – yet. That is expected to come later, and you don’t get around this by booking a codeshare.

• You can’t take advantage of credit card status-like benefits from the airline you’re flying, while crediting to the other. If you have elite status with American or have their credit card, your benefits are linked to your frequent flyer account. If you don’t have that in the reservation, you won’t get your benefits like checked bags and early boarding.

  I actually thought, reading the terms of the JetBlue Plus credit card, that someone flying JetBlue who has that card might be able to get free checked bags (a card benefit) while crediting to American AAdvantage. Barclays, which issues the JetBlue card, tells me that this won’t work.

  The terms of the card say that a customer must buy their JetBlue ticket on the card, and enter their JetBlue account number into the reservation at time of booking, to be entitled to one free checked bag. My read then was that if you did this – and changed to use your AAdvantage account some time after booking – that you’d be able to get the bag benefit.

  However a Barclays spokesperson tells me, “Given the mileage redemption benefit, the customer would not get the bag benefit as well in this scenario.”

The only way you’re going to get elite or credit card benefits from the airline you’re flying, while crediting miles to the other airline’s program, is by checking in, getting your boarding pass, and checking bags while having that airline’s frequent flyer account in the reservation and then changing frequent flyer accounts after check-in.

You may not find an agent willing or able to do this. American actually has a rule against using the benefits of one program while crediting miles to another. You’d be equally happy though removing your frequent flyer account altogether from the reservation, and then submitting the flight to the other program for retro credit later.

Of course this gets complicated when you’ve only checked in for the first part of a roundtrip ticket, since you’d have difficulty taking advantage of benefits on the return portion of the trip. This is much simpler with one way tickets.