u/deManyNamed

It took me about 7 hours of playing and 2 map creations to find a small green bamboo biome. At 4,5 hours of searching on the first map I started doubting that it even existed.

So, the easiest way to find it is:

In generation settings select a warm climate, go south as long as there is plenty of brown bamboo, seek for 38+°C area, about 2-3 hours of search and profit is here