SH plants?
Grevillea 'Mt Tamboritha' is a form originally found on Mt Tamboritha, not too far from here.
Don't know the origin of Coastal gem but assume it is also a selection from the wild here.
Grevilleas have proved difficult as bonsai, at least for me. They are particular about root work and can't be pruned below foliage so you'll need to grow slowly and maintain shape as you go. Most of mine have declined as a result of root problems in pots.
Much easier Aussie bonsai species include: Banksia integrifolia and B. serrata; most Callistemon sp; Many Melaleuca sp; Allocasuarinas; some Kunzeas.
Ficus rubiginosa - from Eastern NSW and Qld is one of the best species for bonsai anywhere. It tolerates massive root reductions, hard pruning, dry conditions, indoor conditions, full defoliation, starvation and more and still keeps growing. It's one of the few species I know that continues to fatten even in tiny pots.
Other good species? Many still have not been trialled enough to tell.
You may find some good tips and inspiration on Victorian native Bonsai club or some of the old photo galleries from Australian Plants as Bonsai shows. Both should come up on net searches but if you can't find enough I should be able to help direct.