It’s the theme that need to be responsive, not Connections; the template for Connections need to be fluid in design so they fit well within a responsive theme. I hope that isn’t confusing.
Anyway, back in March all templates received major updates, Market included. So I really recommend updating Connections [first] and then Market. One of the new features implemented in all template, except Market, was making sure they fit in responsive themes at various screen sizes. Sorry, but I do not plan on making Market responsive ready so if that is a priority you’ll need one of the other templates.