What is the best way to repair a small 20mm tear?

Are patches sufficient or should it be taken to a kite repairer (any recommendations in Sydney)?

So others don't make this mistake: put the wing away properly into the bag as anything hanging out will catch on sharp things such as the corner of the foil mast...

Go to any sail repair shop (or sail maker) and buy some sticky-back sail repair/sail number material and once you have washed and cleaned both sides around the tear just cut a couple of pieces of the sticky-back and stick it on both sides.. Like shown in this pic.

Apparently the silicone which helps release the water from the surface of the wing will mean that sticky-back will only last the session and then you will need the services of Neil and his crew at Barracouta Sails at Taren point - know this from experience with a small foil tear on my Echo

Not all wings have the coating but Duotone do (and they ship some sticky-back and bladder patches with their wings in a little kit)

Patches are actually stronger especially if you put one on either side, as the glue attaches to the whole area as opposed to every few millimeters where a needle and thread go, only doesn't look as good ,unless you cut identical size patches and run it to the blue material and put one on the other wing side so it looks like part of the design.
Clean the area to be patched with metho . The UV from sunlight sets the glue on the patch into a permanent fix.