I have found three ways of referring to the age of wine, the first of which is the most common and simplest:
An adjective such as anniculus, bimus etc.
quadrimum Sabina, o Thaliarche, merum diota
fetch the four-year old wine from the Sabine jar, o Thaliarchus
Horace, Odes, 1.9
ponite turaque bimi cum patera meri
set down incense and a bowl with two-year old wine
Horace, Odes, 1.20
See also: Horace, Satires, 2.8.47 (quinquennis); Varro, On Agriculture, LXV (anniculus)
Stored for x years
genera ... quae quanto pluris annos condita habuerunt
[there are] types [of wine] ... which the more years they have been
stored
Varro, On Agriculture, LXV
This sense of condo is also used for preserving and pickling.
Pressed during the time of x
Using premo + an ablative absolute:
tu vina Torquato move consule pressa meo
you, bring out the wines pressed when my Torquatus was consul
Horace, Epodes, 13.6
See also Horace, Epistles, 1.5.4
Bonus: wine that is older than x years
est mihi nonum superantis annum / plenus Albani cadus
I have a jar full of Alban wine that is more than nine years [old]
Horace, Odes, 4.11