Wirelessly posted (BlackBerry8700/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)

My guess is that the airline/alliance choices are not based on lounges as much as they are on network coverage and thus spending revenue on lounge promotions probably will not yield an enough added income to pass the break eve point for the promotion.

Just my speculation,
Dan