For the wet, humid world of your bathroom, tile wins hands down. Sure, bamboo and cork are marketed as renewable, eco-friendly flooring options, but they're both highly processed -- shredded and reformed and bonded to wood backing. One overflowing toilet or bathtub tidal wave can make bamboo or cork flooring swell up and break down -- or start a case of terminal rot. Plus, cork has to be imported from the Iberian Peninsula area, and the only place bamboo grows well in the U.S. is California (where it grows so fast it can choke out other species in the ecosystem).
Recycled tile is truly durable for wet environments, and it has a low impact on natural environments. It comes in all manner of shapes, sizes, materials and designs, with accent tiles and strips that range from fun to elegant. It's a good covering for your bathroom walls, too. You can design a unique look by mixing tile sizes and layout patterns on the floor and walls. The end result is coordinated and satisfying to look at and touch. Some home improvement stores offer free classes, so you can learn to install tile yourself and save big bucks.