Sorry if thats not very clear.
The fifth precept is to refrain from taking intoxicating substances. The reason for this is to avoid being intoxicated, leading to potential problems like drunk driving, wife bashing, and a thousand other mindless offences especially related to sexual abuses, even leading to murder. When our mind is intoxicated, we lose our ability to control ourselves. If you think a glass or two won't harm you, then I don't see any reason that you should deprive yourself of a little indulgence. But beware, if you don't want to get burnt, it's better you don't get near the fire! That is why it is better to avoid totally.
The beauty of the Buddha's teachings is that you have the freedom to chose. The Buddha never issued commandments forcing anyone to follow his teachings. He advised his followers to be wise to conduct their lives in a harmless and dignified manner. So remember, we have to be wise to realize that freedom comes with responsibility.