Problem with bundler/passenger, installing gem from git

I am using Ruby 1.8.7 enterprise version with rails 3 application. I am
deploying my application by using phusion passenger with nginx.

We have forked one gem and added into our github repository.
I have added in my Gemfile
“gem ‘google_directions’, :git =>

When I do a bundle install on production server it is showing no error
and installation the “google_directions”.
When I do “gem list” it is not listed in my gem list.
When I run the application I am getting following error:-

“git:// (at master)
is not checked out. Please run bundle install (Bundler::GitError)”

I am not sure what is happening.
Also, I have read that gems which are installed through git will not be
listed in the gem list.

Can anyone help me out to solve this?