Gems not in Local Gems after bundle install

Question

New machine. New rbenv install. New rbenv-gemset install. New ruby-2.0.0 install. New rails 4.0.0 app.

When I

$ bundle install

from the rails app directory, I get

Your bundle is complete!
It was installed into ./vendor/bundle

But, if I then

$ gem list

none of the gems that were supposedly installed show up.

I have run

$ rbenv rehash

Why could this be?

Additional info:

$ which bundle
/usr/local/var/rbenv/shims/bundle
$ rbenv which bundle
/usr/local/var/rbenv/versions/2.0.0-p247/bin/bundle
$ rbenv which ruby
/usr/local/var/rbenv/versions/2.0.0-p247/bin/ruby
$ ruby --version
ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-darwin12.4.0]
$ rbenv gemset active
blog
$ which rails
/usr/local/var/rbenv/shims/rails

Answer 1

Your default in this app is to install to vendor/bundle. You can tell this by It was installed into ./vendor/bundle text which appears after gems installation.

Bundler documentation specifies that you have to pass --system to install in system location:

--system: Install to the system location ($BUNDLE_PATH or $GEM_HOME) even
          if the bundle was previously installed somewhere else for this
          application

EDIT: More explanation is that your ruby knows only about gems installed with --system option when not using bundle exec. You can see your gems from vendor/bundle or whatever path you've chosen by running bundle exec gem list or (as Casper noticed) bundle list. Now it is your choice whether you want your gems in system location or in application directory.