Its not a part of ION. On BaanIV portingset 6.1c.08 is required to be able to start a connection through Connector for WebService with JCA connectivity.
Connector for Web Services withe version greater than or equal to 8.5 is supported by Baan 4.
About licensing part, I think you will need the Development license only. Not sure though.
Unless you try to do something beyond what you have already mastered, you will never grow!