As TGMPA - since version 2.6.0 - comes with its own translation files, you can save the translators of your theme or plugin some work, by excluding the TGMPA strings from your .pot file.
WARNING: Only do this if you are distributing the TGMPA translation files with your theme/plugin! In other words: do not do this if you distribute your theme via wordpress.org!
The easiest way to set this up, is by using the program Poedit. So install this first if you haven’t got it already.
.pot file in Poedit.Catalogue ⇒ Properties or just press the key combination Alt+Enter.Sources paths.At the bottom of this screen you can add files or folders to be excluded when generating or updating the .pot file:

You can either exclude a whole directory …

… or exclude individual files from parsing by the .pot generator.

OK and then use Catalogue ⇒ Update from sources to update your .pot file and the TGMPA strings will no longer be included.