You are confusing the Taliban with the Mujaheddin (a common mistake, and not surprising considering the very poor coverage and repeated falsehoods in the media). At this time, the Taliban was just a Islamic religious school, and didn't enter Afghanistan as a political or military force until the early 1990s (after the Soviets had already left and the CIA had stopped providing assistance). And FWIW, the CIA didn't start supporting the Mujaheddin under Reagan, it started under the Carter administration (1979).
The Afghani Mujahidin arose mostly from the indigenous Afghani population to fight the Soviets after their invasion in the late '70s, and received U.S. support beginning under the Carter administration. Today, their remnants are usually referred to as "warlords" in the press, notable among them the loose confederation known as the Northern Alliance.
Usama bin Laden was one of thousands of foreign nationals who flocked to Afghanistan during the '80s to assist the Mujahidin in the fight against the Soviets, and used his considerable wealth and leadership skills to solicit and manage millions of dollars in foreign aid for the Mujahidin, including some from the United States. He also directed hundreds of military operations and gained a reputation as a talented and capable military strategist. Al Qaeda ("The Base") appears to have originally evolved from his Mujahidin and Wahhabist cadres.
Although he was a Saudi, many Afghanis still hail him as a hero for his work in defeating the Soviets and his largesse in helping the Afghani people with numerous public works projects (he has a degree in civil engineering) and Islamic charities. When trying to understand why so many Muslims revere Usama, it is important to remember that he was viewed by many as a sort of Islamic George Washington long before he began his murderous campaigns against the "western enemies of Allah".
The Taliban arose in the early '90s in the wake of the Soviet withdrawal as an Islamic military/political movement to transform Afghanistan into an Islamic state. A great many of its members came from Islamic religious schools (madrassas) in Pakistan, including numerous Afghani refugees as well as Pakistanis and other foreigners who nourished the movement in the interests of "fundamentalist" Islam. While I have seen nothing indicating Usama was the impetus behind the Taliban movement ("Taliban" means "students"), his Wahhabist convictions were completely in line with their objectives, and he became an important and powerful ally. I have seen nothing to indicate U.S. support for the Taliban; if there has been, it would most likely have been related to drug war programs such as opium poppy eradication efforts.
With the Taliban as both an ally and a tremendous source of recruits, Al Qaeda blossomed into an international organization, expanding its reach throughout the Islamic world and gathering dozens of disparate radical groups into its fold. During this time, in the early '90s, Al Qaeda shifted from local insurgency to international "activism", in the form of strategic fundraising, charitable activities ("zakat", or charity, is one of the five pillars of Islam) and militant activities including the support of insurgencies and Islamic state-building in Chechnya, the Balkans, Kashmir, Palestine, southeast Asia, Africa and the Phillipines. Also during this time Al Qaeda undertook a campaign of terrorism aimed at western nations in an apparent attempt to discourage them from interfering with these "Islamic jihads" and the spread of fundamentalist Islam, with successive attacks tending to increase in ferocity, sophistication and lethality.
It is specious to assert that the Mujahidin, Taliban or Al Qaeda were products of U.S. interventionism. While U.S. activities did contribute to their advent, they came into being and would have come into being on their own, regardless of American foreign policies.
What is not in dispute is that the United States will play a key role in deciding the futures of these groups.