I have a very formal set of definitions for you.

Vintage - the year the bike was made. That's it. Every bike has a vintage year.

Classic - a design that has stood the test of time and proven of merit.

Try these definitions out.

You can have a "recent vintage of a classic design" (a new steel build of an old design).

You can have "a vintage 1970 Peugeot PX-10 that is a true classic" (note the old model year for a worthy bicycle).