Green tea is generally mostly composed of water. Of course, that depends on whether you purchase it, make it yourself, etc. Everybody has different "needs" when it comes to nutrients and optimal body functionaliy. More water is definitely not always better... just look up "water toxicity" or "drinking water in large quantities." The minimum amount of water probably isn't that great for a person either.
At the same time, some people feel like drinking water is actually a primary cause of their acne. Just think: most publicly available water is full of flouride, which some link to acne increases.
I'd suggest you test whether your water intake actually correlates with your acne. Perhaps drink a bit more water every day for a month, see what that does, then drink even more for another month, see what that does, and so on. You never know until you try it yourself! And if you do, let us know how it goes!