You should have client task created in the ePO server.
Once the agent on the imaged machine will report to the ePO server, it will enforce the product policies/client tasks.
Make sure that you delete Agent GUID/MAC address before creating the machine's image.
Hmm... could you have a 'Once' deployment task which you would trigger with a cmdagent.exe /p /e /c command line?
No, if you set the task to run once then it will not run next time till it's edited.
Looked at the CmdAgent response and think what I need to do is once the machine has completed the re-image launch FramePkg_AD.exe /FORCEINSTALL /INSTALL=AGENT /SILENT from the ePO server followed by a CmdAgent.exe /e /p - any comments please.