AusBonsai

So I bought this one year ago and after a very long Adelaide winter it has come back to life, I have re-potted pruned and shaped it a bit more, what do you guys think? It was pretty unstable in the original pot so I put it in a bigger one, will the trunk widen any more for me? And also should I try to limit any more upward growth. Thanks!

Could be Chinese Liquidamber (Formosana) We really need a close up shot of a single leaf for positive I.D.

hi stevox,
2 things make trunks thicken. Time and growth.
If this tree stays in a bonsai pot and is trimmed regularly it will thicken but you will hardly notice it over many years.
If you want it to thicken more quickly you will have to let it grow. The usual advice is to put it into the ground or a grow box for a year or 2 and allow it to grow as long as it can then cut back down to bonsai size when the trunk is thick enough. You will get small increase in thickness (but not as much as in the ground) by just letting it grow in the current pot for the year then cut it back hard each winter.
Height and width look ok in the pic so whether to let it grow will depend on how desperate you are to thicken it up.

Cannot quite make out the leaf so cannot idetify.

check out the wiki pages in my signature to get some great info on how to grow and develop the trunk

Ken

Yes, it is difficult to make out but i think hedgerow maple (Acer campestre)

Definitely a Maple as it has opposite buds, Liquidambar has alternate buds. Looks a bit like A. campestre but yes, closeup needed.

Cheers,
Mojo

Trident maple? Hard to say...