Hi Tassie Devil,
As a general rule of thumb, if you want to study at University, then you will need to sit the Academic English test. TAFE accepts the General English test. But there are always exceptions. For any study application, you will need to consider three things: 1) the minimum English level required for acceptance into your course, 2) the "threshold" English you will need to apply for your visa (a student visa normally requires the same level of English as the education provider) and 3) the English level required for professional registration and skills assessment. Normally, the skills assessing authority require the highest level of English.