Bamboo does not contain toxic extractives that would leach out into your brew. In fact, Bamboo Shoots are quite tasty in certain foods. The biggest thing you'll have to be worried about is if it is not a single, solid piece of bamboo, but made with several pieces glued together. The glue may or may not contain chemicals that would be toxic. I never use any composite wooden utensils in cooking or brewing, as I don't want the glue in my food.
Short answer: you're probably fine.