Do I need to install aerial wall outlets or is there a wireless solution

It sounds like you have solid 13/16" thick plywood for a wall. If that is the case, I'd drill holes matching holes in the mount all the way through, get four metal bolts, four matching nuts and eight washers, and hang the mount on the wall, securing with nuts from the opposite side of the wall and using threadlocker on bolt threads. You would have nuts permanently visible on the back side but the construction should be more than sturdy enough to hold a 40 lb TV.

If you don't have solid plywood but something else (I doubt that there's enough room for anything else but who knows?), that's a different story. You should find out as soon as you drill the first hole.

If the top of the plug is shearing off when you put the bolt in, then this means the bottom of the plug isn't turning (so not a problem of the hole being too large), but the top of the plug is turning (which means the bolt is gripping it rather than turning within it).

Looking at the picture of your bolt in the partially failed plug, and given the above, I believe your plug diameter is too small for your bolt. Your options would therefore be to either get smaller bolts, or to get larger plugs (and drill a larger hole for them).

An alternative would be to get a different sort of plug. There is a product called "grip-it" designed to attach to plasterboard (=drywall) which has been installed dot-and-dab over masonry as per your situation. I've found it to work well, but the diameter of the fixing is very large, so is only suitable when the bolt won't be near to a visible edge. The business started in the UK, I have no idea whether it's available in Australia.