Tomcat only supports tyrex.resource.jdbc.xa.EnabledDataSource which means that JDBC data sources are not supported and there is limited connection pool support. EnabledDataSource only supports JDBC 1.1 connections.
You can set the following EnabledDataSource parameters: user, password, driverClassName, driverName. Missing parameters are: pruneFactor (for reducing the size of pooled connections), isolationLevel and transactionTimeout.
To use the Tyrex connection pools you will have to integrate them with Tomcat yourself.