The digger in the photo is from 2nd Battalion, the Royal Australian Regiment, which wears the Australia tartan. The 7th Battalion also wears this tartan, whilst the 3rd Battalion's pipes and drums wears Royal Stewart.

There are a number of battalions in other regiments still maintaining the lineage of Australia's Scottish regiments:

The Royal New South Wales Regiment (NSW Scottish)
The Royal Queensland Regiment (The Byron Scottish)
The Royal Western Australia Regt. (Cameron Highlanders of WA)
The Royal Victoria Regiment (Victoria Scottish)
The Royal South Australia Regiment (SA Scottish)

Just to name a few.

A good friend of mine's grandfather served in the Queensland Cameron Highlanders at Milne Bay in 1942.

Cheers,

Todd