The answers is Yes ^. I flew VS in economy class last week to HK and at Sydney checkin I enquired with the checkin agent on the lounge access. She asked for my SQ card and after viewing it she gave me a pass to access the Air NZ lounge. My bags were also given the Upper Class priority tags. On the return leg in HK, I could access the Virgin clubhouse directly after showing my SQ card at entry.

During boarding VS also allows priority boarding for SQ elite customers - its announced.

So overall, I was quite pleased to accrue SQ miles and also get the elite benefits on the SYD-HK direct route. Usefull alternative to flying QF or CX.