If you want to achieve maximum water efficiency then there is no question that Netafim Dripline is your friend!
Here is a job I did recently in Yanchep where new native plants had been installed and the client wanted to ensure minimal wastage of water. Now that the Dripline is in he can mulch the area.
If you are on a bore then you may like to consider ‘bore line ‘, similar but not pressured compensated – which usually isn’t an issue on a bore.
This dripline is extremely effective at dripping water right next to the plants and is designed to resist root invasion of the drip emitters.
While there is no digging involved in a project like this dripline is a more expensive product and generally works out a little more costly than sprays.