They get paired up with whoever is in their equal spot on the NRL ladder. So, even if we came first we'd be playing our 'home' final at wherever the bulldogs play their 'home' final assuming they finish 1st. The only exception is if on of the 20's teams playing on the day also have their NRL side in a final, they can request for the game to be played at the same ground.
It was rare that we got one at some point last year actually. i think we were one of the few top four sides that actually got one last year. Raiders wouldn't have gotten one, dogs wouldn't have, dragons wouldn't have, brisbane would have got one second week of finals like us...yeah pretty sure not too many teams got home finals lol