This is a species of Septobasidium. The species of Septobasidium parasitize scale insects (without killing them), which in turn parasitize the host plant. The fungus grows into a carpet-like covering over a colony of scale insects.
There need not be any connection. I've seen Septobasidium on young to old plants (of various genera), not too surprising since you can get scale insects on plants of various ages. Septobasidiums are generally some shade of brown (e.g. pale milk coffee brown, rusty brown, blackish brown), often with fuzzy, white(ish) margins, with a somewhat velvety feel and the surface may be creviced. The genus is usually easy to recognize by sight. My hazy recollection is that much is unknown about Septobasidium in Australia.