By e-mail from a chowhound: "Can you tell me anything about this wine? A Bulgarian friend gave me a bottle of 1995 Trakia Valley Merlot from Haskovo winery -- should I wait before I drink it? I generally get concerned lest I drink my wine too soon."
First, please keep in mind the caveats that aging ability is highly dependent on storage conditions and your mileage may vary in taste for older or younger maturity in wine from my own.
Merlot is an early maturing grape variety and one that is approachable for drinking even when not fully mature. The best examples from Bordeaux and California can be plenty enjoyable at 5 years of age. Most Merlots are fully ready to drink upon release and will not get any better with age.
There are few Bulgarian wines that will benefit from time in the cellar. About 10 years ago some were saying that Bulgaria was an up and coming wine region. At the same time, there were rumors that the sudden increase in quality was due to the South African juice that was smuggled into the country and repackaged as Bulgarian to get around trade sanctions. I can't confirm these rumors, but with the dropping of trade sanctions and rise of South African wines on the international market, interest in Bulgarian wine has fallen precipitously along with quality.
I would have assume that your bottle is fully ready to drink today. However, not being familiar with Haskovo Merlot, I searched on google and came up with a Japanese site (that I can't read) offering a 1991 reserve bottling! Does the label indicate any special cuvee names or reserve designation? If so, the producer may have made it in a style for extended aging. Another clue to the winemaker's intention is the cork and glass used. If your wine was intended for aging, it should have been stoppered with a long (more than 2") cork and the bottle probably has a deep punt (indentation in the bottom for collecting the sediment).
If it were mine, I would probably plan to drink it within a year. I'd also have a back-up bottle at the ready in case this one disappoints.