Now that you are rooted, for wireless tether, you want to turn your cell radio off, but connect your phone to wifi. Then go to the market and search for wireless tether. (if the cell radio is on, the app won't show up thanks to Verizon's influence).
An alternate method to get the wireless tether app: if you are comfortable "sideloading" apps, you can do a google search for "google wireless tether" and you will find a website to download the wireless tether app (it is hosted on a google code server, but isn't produced by google). There, you will be able to download the latest beta (3.0.2) or the stable (2.07) versions. The beta is working for me, as long as I select the TB profile, and make sure "routing" is checked in the settings.