Have you experienced the feeling that you open a bottle of your homemade wine and it seems to be a different wine from other bottles of the same batch? I have noticed the difference from one day to the following, so it is not a matter of aging. I know that wine flavor may depend on the context, for example, what you are eating or what you have eaten, but I have noticed big differences in the wood tannins presence, for example. Any explanation or it´s just me?
If your bottle wasn't sanitized properly you may be tasting some off-flavors from bacteria.
This link is based on off-flavors of homebrewed beers but may be similar to wine:
Knowing what type of flavors you were tasting would narrow down exactly what went wrong.
Once a bottle of wine is put in the bottle, it becomes it's own ecosystem subject to whatever bits and pieces of dirt, dust and other crud (insect parts!) that you didn't fully clean out. It's also subject to whatever is in your corks. The most common problem for a winery is bottle variation due to corks. Corks can have the largest impact on wine post bottling. It's important to use the highest quality cork you can afford (or use screwcaps) and make sure you thoroughly sanitize every bottle. But even then you can have the occasional off bottle. Here is a quick wiki article on the topic