The Linux kernel community make use of patches in git to share code changes with one another. Patches are only nicely formatted differences between your current codebase and what you compare it to. If you want to share a subsetted git tree, then git bundle would be the way to go.
Creating the patch
If you want to create a patch based off the difference between your current branch and master, run the following:
git format-patch master --stdout > feature_branch.patch
You can then email the patch to the team.
Applying the patch
To apply go into a new branch and apply the patch file.
git checkout -b feature_branch git apply /path/to/feature_branch.patch