NSW Fair trading states;
The main reasons a claim can be made against the bond are:
•unpaid rent
•the reasonable cost of repairing damage to the premises, beyond fair wear and tear
•unpaid water usage charges, so long as you had requested payment within 3 months of receiving the bill
•any 'break fee' or other charges payable as a result of the tenant breaking the tenancy agreement early
•the reasonable cost of cleaning any part of the premises not left reasonably clean, having regard to how clean the premises were at the start of the tenancy
•the reasonable cost of having the barrel of the locks changed or other security devices replaced, if the tenant has failed to return all keys and security devices they were given.
This is not an exhaustive list. There may be other legitimate reasons for making a claim against the tenant's bond, such as the cost of disposing of goods left behind by the tenant. The claim must relate to a breach of the tenancy agreement by the tenant.
So yes, you can claim the change of locks. If you apply to tribunal for a bond and compensation claim then you will have an order for the WHOLE amount, rent and all, your landlords insurance may require this to pay out on the claim. Then you don't chase the debt as it has been covered by your insurance.