I know there is a huge debate about the toxicity of Pine and ball python snakes. I don't want to restart a debate so I will put it this way.
I wouldn't have the bin open facing any unfinished wood. Your going to face warping and mold due to the humidity in the bins. If you have a finished panel of wood than the type of wood doesn't really matter as there is a barrier between the animal and the material. More than anything it's important that the wood be sealed and finished.
Hope this helped.
Chris.