In the earlier incarnation of the ABTA, teachers were required to complete a simple written exam as part of the process of becoming a member of the ABTA.
This was basically a rough test of playing ability, rather than a measure of potential as a teacher.
We may implement an updated exam but the ABTA does not seek to have a role in the Accreditation of teachers. Some states (notably Victoria) have their own Accreditation process.