I would like to see less emphasis on the word 'Australian' and more on 'Nature Photography'.
Also, I'm not sure what the objects in the picture are. Do they represent stars? In #31 and #32 they look a little like snow which we don't get much of in Australia :-).
I do like the concept of the logo being a photo like you have done, but I think the content of the photo should be a little more 'Australian' and easily identifiable as nature related.
#33 - I like the symbol. I'm not so sure about the text. I think 'Nature Photography' should probably be one a single line and with an uppercase "N" in nature and not all caps for photography.
I prefer the lighter feather tips in #33 than in #34