try this...
ttmra
pg 6
Medical Certificate
A current medical certificate is not required when applying for an Australian licence under the
TTMRA, as it is not a prerequisite for licence issue. However, applicants will need to obtain an
Australian class 1 medical certificate before they may exercise the privileges of the licence.
However...
DAME newsletter
Thus CASA may allow the New Zealand TTMRA applicant to use his or her
New Zealand civil aviation medical certificate to validate a class 1 licence issued under the terms of the TTMRA until the NZ medical certificate expires (instead of issuing an Australian medical certificate).
may be my interpretation of the rule but does this suggest that the kiwi one is ok until first renewal? I guess the 'casa may allow' are the key words...