As of 7.2, the "session" information you can retrieve from the server for the connection does not contain any information about which node you connected to. The session is not shared across the cluster, and connection has the affinity to the node it connected to by default. If node goes down it will re-authenticate with next node provided in the URL. See this http://docs.jboss.org/teiid/7.2.0.Final/client-developers-guide/en-US/html_single/#multiple_hosts
Since Teiid does not share sessions across nodes, it may be useful to have the information you are asking to determine which node the client connected to. You can request this as an enhancement.