What was the last grand tour won on an aluminum frame? Also, any details about the bike itself and the rider would be appreciated.
Abraham Olano won the 1998 Vuelta on an alloy frame. That might be the last Grand Tour win on alloy - as the Vuelta is the last Grand Tour of the year.
According to this article, the last Tour De France win on an aluminum frame (a Bianchi ridden by Marco Pantani) was 1998.
It also says that the last TDF win on a steel bike was 1994. It's interesting that aluminum had such a brief run.