Money alone doesn't bring happiness but you can use money to get lot of things that can make you more happy...better education for your kids, nice house, holidays abroad, some luxuries etc. But if getting more money & wealth becomes purpose itself you can never be happy because you want more and more.
But having none doesn't make you happy. In normal situation you need money for your basic survival: roof upon your head, food, clothes etc.
I have noticed that many bohemian people who claim to possess only the clothes on them and be happy in reality have wealthy relatives and friends to pay their lifestyle for them. And the ones who don't have those resources might be happy and "feel free" at first but the constant improvised struggle for survival burns them out and sooner or later they usually hit the wall. I have heard saying that goes bit like this: bohemian in the 20s, junkie in the 30s and number in the suicide statistics in the 40s.