Not so, people who make wine speak about their "wines" all the time, meaning their different varieties or types or bottlings. Also, sommelier who has 635 different wines on the list. Or we had 6 wines with dinner, ranging from a sparkler with the hors d'oeuvres to a 1963 vintage port with with the cheese.
There is a difference in use. You enhance a program by extending existing features or adding something to it that will improve it. "improve" is a more general use and includes anything that would make it better. You could choose a tastier variety of grapes and I would say you improved it. You could enhance the label of the wine by adding something to it, but then I would not say you improved the wine. http://english.stackexchange.com/questions/105465/difference-between-to-enhance-and-to-improve