I was trying to figure this out a few weeks ago with MeteoBRIDGE, but didn't get the link between the two sites until you just posted it. When I just set it up, I had to use my station ID and not my PWS logon ID for my credentials in MeteoBridge.
FYI, I'm sending every minute, and there is a 3-4 minute lag in the data being displayed on PWS. Don't know if that is normal or just because it is a new station feed, but it did take a while for the first data (and subsequent updates) to show up in PWS.....