Emailed them with my UA 1K card. I got the following response: "Customers with residence in the US must prove a booking confirmation incl. booking number of an airberlin long haul flight between US and Europe (return ticket). This flight must be operated by airberlin and take place in 2017/18." I sent in my itineraries to Germany via Star Alliance carriers, but that still wouldn't do. So I made a booking with Airberlin, and was approved to Gold. I requested Platinum and the response was: "A match on Platinum is possible only with a Lufthansa Hon Circle card."