gitignore is used to ignore all the unnecessary burden over the git server and your fetching all the time.
So the best possible stuff to put inside the gitignore is packagable entity. Now, this includes the meteor downloadable packages, so, you should just add ".meteor/local" inside gitignore.
When you add it to gitignore configuration, it reduces the size of project to n times smaller as it would be with the packages.
If you cut-paste the entire project now to different location or fetch the repository without .meteor/local folder and start the project using meteor command, the meteor first downloads the required packages and then starts the server.