The way I look at bikes is from 1970 on (I know you can go back way further, but let's not talk about that).
1. Steel Frames / Campy Components (All Vintage)
2, Friction shifting (All Vintage)
3. Carbon, Aluminum, Ti Frames, Shimano, SRAM comes into the scene (There are Al, C & Ti Frames that are vintage, the Litespeed C1R for example, not to mention the C/Al Frames)
4. Index Shifting (about 1985 or so)
5. Brifters (I hate that term, I think it should be Shifting Brakes or Shakes)
6. Aero Frames (about 1985), they are already designing frames that get "lift" like a wing or sail... these will be vintage.
7. Disc Brakes, the first hydraulic systems are vintage (1971 Stingray)
8. Electronic Shifting (1990)
So where does Classic & Vintage Start, where you want... The year really doesn't matter, it's the technology and the demand that makes it vintage & classic (and even more so, it's personal perspective...) In my opinion, when a new technoligy hits the market (weather it succeeds or not), it becomes vintage /classic, the Chevy Corvair is vintage & classic no matter what Ralph Nader said...
My 1974 Mirella record group bike is vintage & classic, but so is my 1999 Waterford 2200. And if I get a 2016 Litespeed C1R (with any luck this summer) it will be vintage and classic as well)...