Well it doesn't look available for AU. Also the category trees are completely different. In the US you can only choose Books->Childrens books and that's the farthest level down. AU lets you go much further in the category tree.
I tried choosing some categories on the eBay.au sell your item form on eBay's site and I couldn't find anywhere that I could get the prefilled item data by entering an ISBN. Perhaps it's not even available there?