I don't know about Australian deaf peer support but the UK version is fraught with problems and concerns about deaf people's rights to privacy not being respected, and peer support/mentors' not qualified enough or monitored, it just seems the only qualification is an ability to sign and the entry level for that is suspect.
After watching 'peer support' application in our deaf clubs where the support often and openly discussed the client's private issues, it would be a definite NO from me! I don't think peer support should be provided by 'friends' who attend the same clubs either, it's wide open to abuse of vulnerable deaf. Local authorities that fund peer/mentor help are trying to save costs by allowing just about anyone who can sign to act as support, trawling BSL classes for volunteers! Many deaf who need e.g. home helps get nobody who can sign to them at all, including some deaf clients with Alzheimer's... this puts the deaf at far too much RISK.
No interpreter can work without an acceptable level of sign accreditation and a rule of non-interference and advice, both of those vital rules do not seem applicable to 'peer' help or mentor help. While proper monitoring of peer support will help a lot of deaf, what happens if that client does NOT sign? there are no 'peers' at all being trained to support them. So no provision is available...