The answer to this question hinges on whether or not you are reproducing any creative visual elements of the menu or if you are simply listing the text of the menu on your website (similar to menupages.com).
If you are simply reposting the text of the restaurant menus, then you will likely not need to get the restaurants' consent, as there is generally no copyright protection in the basic descriptive content of a menu. If you are posting a picture of the restaurants' menus, then you could potentially be infringing on their copyrights, depending on the originality of the menu in question.
The U.S. Copyright Office has a relevant link on the copyrightability of recipes, that may be useful reading.
