This is a hidden benefit of belonging to a wine club. Often you can talk to the wine maker and/or they are opening enough bottles regularly that they can give you a sense of when it's time to drink. After you've been through a few years of the syrah or the cab sav, you get a sense for yourself too because you start to get the pulse of what the winemaker is making.
This is actually the first year in a long time that I have a batch aging -- using wild grapes growing on my property. The first wine I ever made (from a kit), unbeknownst to me, needed to be aged to taste good. Once I learned that, I did the same test: every few months I'd open a bottle and taste it. After a year, most of the "tarry" flavors were gone, after 3 it was getting good. At five I really liked it. Unfortunately, no bottles survived to the 10-year mark, but I did learn to make wines that matured a lot faster!
One of the fun things is that you don't really know exactly the optimum amount of time to cellar a new vintage. So there are online forums where people will buy a case and open one bottle a year and report their results on how the quality changes over time.