I was going to make a similar comment. Bamboo is not the usual habitat of Feathertail Gliders (or Sugar Giders for that matter). Maybe the enclosure was meant for something else and the gliders are in here temporarily?
Be the exhibit as it may, I find this picture simply terrific!!! I wish more people would take such photo's of the exhibits. Helps me incredibly with my research about the captive management of Sugar Gliders and other arboreal marsupials! So Zebraduiker, thank you for posting this photo!!!
Eucalyptus (the most occouring plant in habitat of feathertail gliders) is not responsible for the furnishing of enclosures suitable for feathertail gliders. They have a very high metabolism (cause of theier exudivore and insectivore nutrition), so you must set up the enclosure to be cleaned quickly and easily be replaced. In australian zoos the "natural device" is easy to get. In eropean zoos, australian plants (they are usually under protection and may not be exported) hard to get - the expense for the "natural institution" would be nonsensical. I think bamboo is a good compromise for this enclosure.