The status of the sponsoring member has NO impact. I know this because when my wife and I were wait listed on the same file YVR-YYZ, where I am Elite and she is Prestige, the gate agent called me up and issued me a biz class boarding pass for the second last seat and then called up another Elite member for the last seat. I was told my wife would have been next but the wait listed Elite member trumped my wife's Prestige even though it was my upgrade request on my e-credites on a joint file, not even as a nominee.

I of course offered my wife my biz class seat but we agreed to refuse it and sit together in the first row of economy (as previously reserved). What i don't know is who got the seat we turned back.