Currently, the 'australian' tag is used to represent the Australian Aboriginal Dreamtime stories.
However these stories aren't 'Australian' in terms of the current country & the culture introduced by Britain's subsequent settlement. Just as Roman myths and legends are known as roman and not italian, they are unique to the Aboriginal culture and thus should be tagged as such.
I propose these questions be retagged australian-aboriginal or australian-aborigines.
'aboriginal' can be used to represent the original peoples of the world over, not just Australian aboriginals, thus it probably shouldn't be a tag to represent just Australian Aborigines by itself