From what I read in this thread, it appears the guidelines are open to the rangers' interpretation there, same as here.
I've gone through the Queensland Parks document, and its all worded in a generic sense..."camping unit" etc.
One thought I've had while reading this thread...I wonder is it worth pre-empting possible problems by incorporating maybe a piece of 1 inch strap for the tarp line? Just going by the fact that rangers are often persuaded when they see the tree straps. Down the road as hammocking gains a bigger profile, and authorities might want more specific rules, maybe the tarp lines could be a stumbling block ?