You can integrate HCL iNotes and/or HCL Verse on-Premises, with Sametime 11 via ST Proxy server, the same way the integration was done with Sametime Version 9.0.1.
But before you can integrate the products mentioned above, you have to configure Single-Sign-On between Sametime WeClient and iNotes/VoP.
With Sametime version 9.0.1, you would export the LTPA Token from Websphere Application Server and import it in the Domino “Web SSO Configuration” document of the iNotes/VoP server and Sametime Community Server. Thus making sure that all components involved are using the same LTPA Token.
But in the Sametime Version 11, we do not have any WebSphere components. So, you just have to make sure that the Sametime Community and iNotes/VoP servers are using the same LTPA Token. Either export the LTPA Token from the old Sametime environment or any other existing WebSphere server and import it in the relevant Domino “Web SSO Configuration” documents. After restarting all components involved, the SSO should be working and you can proceed with integrating Sametime with iNotes and/or Verse on-Premises.