CA TPX uses SNA protocol to connect to VTAM. It is not designed in its present state to accommodate TCP/IP as the protocol for VTAM application access.
The only "non-VTAM" type of connection supported by TPX is through the TCP-Access Interface. Other than that all connections to and from TPX are VTAM LU type connections. So SSL would not come in to play.
Release: NVINAM00200-5.2-TPX-Session Management-Access Management package