Yes, if you have guests from more that only your state, you could obtain a federal trademark registration assuming that the name is registerable (for example, it is not descriptive and is not similar to the name of another B&B).
However, obtaining the trademark registration will not prevent someone using the name of your bed & breakfast in a site that is simply complaining about it.
Answered on Oct 10th, 2013 at 3:23 PM