Clinton had from 1993 (WTC 1) to go after bin Laden, at the latest 1995 (Embassy attacks.) During Clinton's presidency their were CIA operatives that actually had bin Laden in their sights, awaiting clearance to take him out. The NSC at the time would not sponsor the strikes.
As of now, there is no evidence that shows that bin Laden has even been clearly identified by any US operatives on the ground since GWB took office. Was bin Laden allowed to slip out of Afghanistan and into Pakistan during GWBs presidency? Most likely. Did the NSC, since 2001, actually make the call to let him go? No! Since then, GWB has stated that if he were provided actionable intel on bin Laden's whereabouts, that our troops would invade a sovereign nation in order to get him.