Yes, I believe that Oz uses +/- 2 NM for pilot tolerance on the arc (unless stated otherwise on the chart). I've always wondered how they arrived at this figure because, when I crunched the numbers based on Pans Ops design criteria (many, many years ago now), I came up with +/- 1 NM. Hence, the pilot tolerance for DME arc in PNG is in the books as +/- 1 NM.