3 column Minipanel is not converted into a single column. Instead it is changed into 3 very narrow useless columns for mobile phone users. The code should allow 3 columns up to ipad but force 3 column to become 1 column for iphone. The simplest way to achieve this is to copy the code from Responder module.
I have found that Responder module and Bartik Responsive theme are complementary. Responder is good in converting 3 minipanel block column into a single column where as Bartik Responsive (and all the responsive themes) are UNABLE to do just that but they squeeze 3 columns so that no one can read theme easily. In the other hand, Responder module is UNABLE to control superfish menu but use the main menu instead and damage its css. I would suggested to developers of both sides to combine their projects and effort in order to revolutionize Drupal responsiveness.