I believe it's an escaping problem.
I can set the current ruby version like this successfully:
rbenv local 2.0.0-p247
or this:
rbenv local "2.0.0-p247"
But if I escape the quotes, I get an error exactly like you get (notice the quotes in the error response):
> rbenv local \"2.0.0-p247\"
rbenv: version `"2.0.0-p247"' not installed
Note that usually quotes are not around a a bogus version:
> rbenv local 2.0.0-p111
rbenv: version `2.0.0-p111`
So, in conclusion, I'm guessing that the bundler-less system ruby is invoked in your first snippet, and you haven't yet seen a successful attempt to try bundle with the rbenv managed version due to the RBENV_VERSION quoting issue.