I'm sure Bush is quite familiar with Wilson.
Bob is talking about HIS own source...NOT the first person to go around blabbing about Valerie, which was Joe Wilson for sure.
Bob had sources for his story. He has said there were two, and they were in the Administration but not in the White House. Many have speculated he could mean someone at the State Dept. and/or the CIA.
(He also checked with the CIA to see if they minded the info about Valerie appearing in his column and they did not mind. LOL, because later they asked for a Justice Dept. investigation into possible lawbreaking due to the supposed outing of a "covert" agent.)