I got basically the same offer this evening, though at first I thought it might be some sort of phishing scam because it takes you to a myusairways.com page and then to a usairwayspreferred.com page. I didn't realize US owned all these domains, though it seems like those are legit sites.

Still, it bothers me a bit that if you go through to the buy-up sign-up page, it doesn't seem to say anything there about the club membership. I'd hate to take them up on the offer and then find that something wasn't registered and the club membership doesn't get included after all.

If anything, I'd be interested in buying up to Chairman's Preferred since it has more useful benefit to me. I wonder if that qualifies for the Club membership too (though my guess would be no, since the email didn't say Platinum or Chairman's).