Consider using Git submodules as you start to add 3rd party frameworks, scripts, and plugins. Submodules make managing dotfile dependencies so much easier.
If you get fed up with submodules, many people prefer git-subtree, which lets you merge subtrees (other repositories) into one Git repository, and later split and push changes back out.
If you use multiple machines that are slightly different, you can have a branch for each one and pull changes between them. For example, you may want to use your text editor configuration on both mac and linux hosts, but need different shells settings on each.