Hello,
the social assistance office doesn't care if your room is part of a WG or a flat.
Show your hiring contract to your local social assistance office before you sign it to make sure the social will pay the costs!
Informations in brief see SPIEGEL Online:
http://bit.ly/2aZz2bl (German text).
These informations are designed for German refugee helpers, but they respond to your question).
Detailed informations concerning social benefits and housing see
http://bit.ly/2aZA2fF (German text).
Kind regards, Jan