Maybe I need sleep. I am confused by your question. Your BIS connection is a data plan provided to you by your carrier to allow you to get push email, and use the other blackberry features such as the Browser and BBMaps. What is it that you're trying to do, if it's not tethering.
I think you may have the terms confused. WAP is Wireless Access Protocol. It's basically a format web pages use for mobile browser to view the page.
This may help. BlackBerry Glossary - BlackBerryFAQ