If this has been discussed/answered before, please refer me to the appropriate thread/post. Thanks.

In the general case, there are three airlines potentially involved in any single flight on which you earn miles:

1. The airline you're flying with
2. The airline you're earning miles with for this flight
3. The airline with whom you earned your current status for the alliance that airlines #1 and #2 belong to

(I suppose with code-share flights there can be four airlines involved but I'm ignoring that level of complexity.)

In most cases, I imagine that airlines #2 and #3 are the same but my query relates to the situation where they're different.

I've recently divorced QF and am earning all my OW miles on Asia Miles now (I've done the same for Star, divorcing UA and switching to KrisFlyer). Since I'm starting from scratch I have no special status in Asia Miles. However, as I'm QF Platinum and hence oneworld Emerald for the rest of this year, I can still use CX First Class check-in and lounges, but in order to do so I have to show my QF card with the little Emerald icon on it. Swiping that card enables them to generate a lounge invitation for me but I get the impression that that action also overwrites my Asia Miles membership number for the current flight and they have to manually set it back again for miles-earning purposes. If I don't show my QF card, I will just be told to go to the economy or business class check-in as appropriate, and I'll be given an invitation only for the business class lounge (assuming I'm flying business class).

This rigmarole wasn't necessary when I earned QF miles on CX, as my QF/OW status seemed to be automatically communicated to CX.

This raises a question:

Is it possible for an airline to store your alliance status separately from your status with that airline, and to be aware of it when granting privileges such as lounge access and waitlist priority? Or is presenting the card from the other airline with whom you earned that status the only way to communicate that information to the airline you're flying with (assuming they're different airlines)?

You will never have any status in Asiamiles -- it doesn't include status, that is in a separate program, the Marco Polo Club for CX. You earn miles in Asiamiles (for redeeming awards), and you earn status in MPC. You have to join MPC to earn CX status, and this is separate from Asiamiles. Also costs USD 50, though that fee is often waived if you have significant activity.

FF status is stored in each PNR. You have to show your card to get lounge access, etc. The PNR can contain 2 FF numbers: 1 that earns miles, and the other that is there just for status. This is implemented by all OW computer systems, but 99% of agents are unfamiliar with how to do this. Somewhere on FT there are several posts that give the key sequences that agents can use to add the 2nd FF number, without over-writing the first one. Obviously this is different in each system. When done right, it works very well. But expect some agent to accidentally change your FF number for every segment of your PNR, at some point -- so this can be considerable hassle.

You need to join the Marco Polo Club for the OW status. Instead of doing on line, you can call them direct and see what they can do. They may waive the USD50 joining fee. If you have actively flown on CX/KA metal recently, they may be able to give you a higher tier status.

Thank you both for this useful information.