During my 3 hour 2Es opening from New Zealand last week (see post below for log), I also heard racing on 91.1 and 92.5, but did not ID them.
After doing some internet searching, I believe 91.1 was LiveSport Wairarapa. This makes sense, as Wairarapa is located on the North Island, close to Wellington.
After further looking, 92.5 may have been TAB/Sky Sports Calcairn or Mulawalla, both in Southern NSW. Unfortunately I can not remember and did not take note if the racing on 91.1 and 92.5 were the same or different, so I won't be adding them to my log due to the uncertainty.