CX has an excellent RTW desk in North America, every bit as good as AA (and AA is very very good), but the number is unlisted (you will get it if you qualify). BA has an abysmal RTW desk, reachable only through transfer from the normal reservation line. QF also has a RTW desk, somewhere between BA and CX in quality and most likely to make mistakes in the booking (both against and in your favour). Not sure if they have a separate phone number as I gave up trying to use them. The big advantage to using other than AA is that AA must hand-write tickets with more than 16 segments while the other airlines can issue them by computer (I think QF has a 50 segment max limit, don't ask how I know this).