Bottles of wine should be stored horizontally to allow any sediment in the bottle to settle and fall to the side of the bottle, which prevents spoilage. This will help your wine age well. Storing your bottle of wine horizontally also allows the wine to be in constant contact with the cork, which helps prevent any air from getting into the bottle.  If the wine has a screw-cap top, you can totally store these bottles upright, but they will also be fine if you store them horizontally.