Why isn't there a COS in Australia?
What drew you to this conclusion? The Church of Satan
is a worldwide organization with any number of representatives and members in Australia.2- Who makes the decisions in this area?
Not exactly a well-worded question. I assume you mean to ask who heads the Church of Satan
in regard to Australia (rather ironic since you assumed the Church of Satan
had no presence in Australia with your first question).
The Church of Satan
is headed by High Priest Peter Gilmore and his wife, High Priestess Peggy Nadramia. They administer top-level church functions on an international level, including Australia, from the headquarters in New York, NY.
I'm also not sure what the status of Satanism as a minority religion has to do with acquisition of information, since it is a minority religion in the US and everywhere else. The basic literature, including the five books authored by Dr. LaVey, and the two books authored by Magistra Blanche Barton, can be ordered from the CoS Emporium
or from amazon.com. The CoS webpage, or course, is available for free internationally (except perhaps in some countries that censor it).