It turned out to be bogus- instead of using the funds to fight the Russians it appears he had used all that tithe money to build his own reputation, his own pockets, and his own terror network- the most he did was fund schools, although those were really nothing more than recruitment and training camps for future terrorists.
He was so radical the original group to which he belonged broke from him during the Afghan-Russo war and they went one way while he got even more anti-western. As I understand it, one group wanted to focus their efforts solely on Afghanistan while bin Laden wanted to globalize the jihad and spread it as far as possible. Of course, after the group broke apart, he did just that and really wasn't much use against the Russians at all, though after the Afghans did win- with US help- bin Laden was quick to try to take credit for it.
Yet no one in the press questioned his claims, and no one wondered where he had put all that money well-meaning donors had given him to "free Afghanistan from the Russians," Not even when his grandious claims of bunkers and tunnel complexes turned out to be false.
Bin Laden has Yemeni roots & Palestinian mentoring- the Yemenis tend towards the most militant of the sunni/wahabbist sect of Islam and the Palestinians are... well, Palestinians... the mercenaries of the islamic world. He had all along been putting the money into building al Qaeda, and organization which was not created after the Gulf War as so many think, but years before that.