Rule of Thumb:

Put the year the "fruit" was harvested, or if you don't know (i.e. if
you get frozen ingredients or such) then the year you began
fermentation.

If you wish, simply put a "bottled on" date as well...



I personally feel it is more important to know how old the wine is,
much more so than when it was bottled...but certainly that may not be
how you feel, so do whichever makes more sense to you...