You CAN be advanced promoted to Pte (T) in advance of the 30 month deadline, if, as in the scenario I've laid out below, you had been granted credited time towards pay & promotion upon your enrollment for courses/qualification you had upon joining. If those are credited as "prior service." It happens...reserves come in as Pte(B)IPC2 and then receive their hook after serving 6 months. This is not considered an accelerated promotion which is what your reference refers to. These guys are still eligibale to be recommended(and granted) one accelerated promotion later in their career.
Accelerated promotions are whole different beasts. You can not receive an accelerated promotion to Pte (T). A Pte (T) can be recommended for accelerated promotion to Cpl, but they can not be granted that acceleration until they have reached the 36 months of service TI and have met the qualification pre-req, and have a very strong endorsement by their CoC. Once they have been granted this acceleration, they can not receive another one in their career.