Hi Fred,
NCM product was probably integrated using a NCM integration module which is an exception amongst orion products. It was used becouse NCM historically used different database. There is no such thing for WPM product. To integrate WPM with other products, you will need to install it to main server. Beware that WPM has to be configured to the same database as NPM...
If you happen to think about installing WPM Additional Website application, I must warn you that it won't help solving your problem. Installing Additional Website on Orion Server will result in error. Only same types of application (main server, additional website, additional poller) can be installed on one computer.
-Z.