For an ale to age for even a full year would be exceptional today. Supposedly, the Romulan drink ferments for an exceptionally long time and for that reason is so intoxicating. But any Earthling reading a date off a bottle of ale today and seeing a year different from the current one would be justly disgusted, feeling that the bottle has been ruined. It wouldn't require a decade, just the simple fact of it not being the current year.
Sure, ale may be preserved for a long time once bottled, but the quality is not supposed to improve with time, except for special brands (or so the marketers of those brands try to claim). Then again, if the Romulan stuff has been fermented to have something like 15-20% alcohol content, its odds of surviving storage also go up significantly...
As for the stardates, if a TNG-style thousand-dates-equal-a-year system is assumed, then obviously we are missing a fifth digit that would denote decades. It would be easy to assume that ST2 takes place a decade or more probably two after TOS, meaning a movie SD 8130 comes 12 or 22 years after a TOS SD 6130.
OTOH, the stardate of ST:TMP, SD 7140, cannot be from the same decade as the stardates of TOS, because the interval between this and the highest TOS stardate (SD 5943.7 from "All Our Yesterdays") is less than the required 2500 units that Kirk has been holding a desk job. So it would seem that TMP takes place eleven years after "All Our Yesterdays"... Which is a very good fit, actually, allowing for the aging of the characters, for all the promotions, for all the technological changes and so forth - and for the fact that more than 300 years have passed since the launch of Voyager Six. Heck, TMP will then take place in 2279, which matches the "300 years after airdate" model that was in all probability highly influential in making the writers decide that it had been more than 300 years since the launch of the Voyager program that in reality got off the ground in 1977.
Taking the model to its conclusion would put ST2 in the very next year, though, or then eleven years in the future - and while 2290 is a possibility for ST2 in some respects (including the subsequent progression of movies, culminating in the solidly established 2293 for ST6), it makes it almost impossible to reconcile with the "15 years ago" or "20 years old" references in there.