First up I am not familiar with any waterproofing standards in NSW, there may be something that applies I am not aware of.
120 up the wall should be ok unless you intend to have the water on the floor deeper than that.
As there is wall penetrations for water to the basin these should be sealed at the openings, Any leak at the tap is stopped from getting into the wall with the waterproof all the way to the floor the wall below any leak is also protected.