We stayed in the Lindrum last Christmas. It's definitely gay-friendly with a significant quota of gay staff who are happy to help guide you to whatever you're looking for. In terms of location, it's in the CBD, and there aren't many gay bars or venues close at hand (despite the huge number of bars and clubs in the CBD, it appears that there isn't a gay one!)

Public transport in Melbourne is pretty good so it's easy to get about but if he wants venues in walking distance he should think about being in St Kilda or South Yarra, or maybe Fitzroy.

PS- tell him not to expect views from the Lindrum - most rooms look onto a multi-storey parking lot or blank wall.