Install pathogen in ~/.vim/autoload:
mkdir -p ~/.vim/autoload
curl -so ~/.vim/autoload/pathogen.vim https://raw.github.com/tpope/vim-pathogen/master/autoload/pathogen.vim
Clone into .vim:
git clone http://github.com/jwhear/vim-bundle.git bundle
Grab the submodules:
git submodule update --init
Create symlinks in $HOME:
ln -s .vimrc ~/.vimrc
ln -s .gvimrc ~/.gvimrc