I am not sure if there is but i know that you can take the monorail either to the contemporary or to the magic kingdom and from either of these places take a boat over to the wilderness lodge but i think these are the only two places that have boats to the lodge
But if you do that route, you must take the escalator down to the 4th floor, the elevator down to the ground and walk out to the boat dock. If you go by boat from the Polynesian (and a fun little boat it is), you just have a short walk to the other WL/FW boat.
But all the transportation options in the MK area make for fun travel.
Monorail to MK and then a bus to WL is probably the fastest. While walking to the bus stop you would also be able to see if the boat to WL was coming. The boat is relaxing but not fast.
Thanks everyone that gives me a few options. I never thought about a walk from the CR. Someone told me previously that there was a boat directly to WL from the Poly, and I did not think that was correct. Thanks for all the choices.