Yes, you need the -smp parameter set, the only work available for OS X and the V6 client is SMP only. An earlier version of V6 for OS X was released with that set as a default, the 6.29 currently available may not have that set already. It has been a while since I did a bare install of V6, so my recent installs inherited an already configured setup for folding. I have not looked at the directions available from Stanford for V6 and OS X recently, but the last time I did they were a bit out of date.
As for the -advmethods parameter, I did come across a notice from one of the PG members that the OS X units still had that setting back in around October or November. That should improve your chances of getting work. The units for the projects available to OS X and V6 are fairly stable anyways, I think most are actually off advanced for Windows and Linux folders.
P.S. I went looking for that message, I think it was this one -
viewtopic.php?f=18&t=20021&p=198976&hilit=+OS+X+advanced#p198976. It might have been changed since then, but I have not seen any posting.