Booked today a tix for my sister and I, LAX-SYD. Problem is I wanted to burn an ECV from an IDB. Well DL agents swear that you cannot book on the same PNR if only 1 voucher is used (ie for me vs companion). Thus in order to book it they must split the PNR's and can link them.

According to DM agent and supervisor, this will have no effect on the GUC's. In other words we can both waitlist still and that it will not affect us clearing the WL.

I'm paranoid that my sister (only being a GM) will not clear since she is not on the same PNR, and because we are linked that will prevent me from getting the upgrade as well.

Are my fears founded or should I believe these DL agents?

Also to add, logged into my PNR and there is no mention of SWU requested or waitlist...