Gidday NZnuka,
Keep at it bro its differently a game where you learn by your mistakes.
Kanuka is good bow wood. But i believe its strength's lie in its ability to handle compression. It is one of our better native woods and is readily available.
Other native woods that i have tried that are good enough in tension to make a bow are generally not very good in compression.
When i lived down the coast i made a few bows out of southern rata, That stuff is tuff as but i did have a couple get compression frets around the pin knots but that was more down to my poor tillering.
Northern rata is funny stuff, lighter and weaker than you think it should be.
Lancewood is another that seems elastic in compression but can be a bit weak under tension especially with that rope like ridges on the surface,
I have made quite a few kids bows out of that have worked quite well but not a decent adult size bow as I'm yet to find a good stave that isnt full of twist, i think it would be a good candidate for sinew backed bow.
I have made one sapling bow out of akeake, that stuff is as tuff as nails. I would love to get my hands on a decent stave of it.
Kowhai is a bit disappointing, its very good under tension but average under compression. its seems to want to soak up moister and take alot of set
you want a stave with a naturally reflex and heat treat it, may be good for sapling bows.
I have made a couple of bows using black maire as a belly wood and it is very good for that, I would like to make a self bow from it but it doesn't grow in my neck of the woods.
The one small bow i made out of Tawa seemed pretty good, i think it wants to be treated like ash or maple and made a bit wider and longer.
Tanekaha is a soft wood that is very good in tension but pretty poor under compression or though i have made a couple of bows from it that have worked one was a sapling bow the other was a sinew backed Californian type bow.
Almost all of our hard woods are diffuse porous so there is not a need to chase a ring.
We also have a lot of northern hemisphere woods here. One that is fairly abundant in my area is black locust, Its makes a nice bow and is a good teacher. You have to chase a ring but if you ever get hold of an Osage stave then you ll know what to do.
These are just my own experiences so far others may have different ones.
Hope this helps.