Guy Betsy,
My experience mirrors yours (although as an MPO Diamond, I am being allowed to waitlist three flights for friends coming over to visit me from SFO around Xmas), but note that what chuck1 is looking for is the YVR-JFK leg rather than the transpacific. I'm not sure whether that is as full as the HKG-YVR.
Nevertheless, I understand that there are different U quotas for CX and for OW partners. (I have a situation where I can get an award flight on CX miles, but not on some BA miles). However, at the moment (I called out of curiousity) there is no availability to me either for U on those flights.