In the New Testament it does refer to men being able to leave his parents but cling onto his wife (singular) and then they become one body, so it's saying that A man and A woman join in holy matrimony and no more.
Also it refers to the necessary qualities of a bishop, one of which is having only one partner. So if the holiest of poeple can only have one partner then surely that is a guide of how the rest of us should live. However before the New Testament it doesn't specifically condemn polygamy.

Ethernium: Whether I agree with the scripture or not is immaterial. I have merely answered the question of what the Bible says on the subject at hand.