As Twitter Bootstrap still lacks out of the box RTL support to its frameworks, we still need to do the extra step and RTL the framework. Now with tools like RTLCSS, it's becoming easier and faster to add the RTL support to the framework. Not only did they do that, but also they're offering a CDN where you can directly link and use the RTLed version.

Check it out at http://rtlcss.com/cdn/css-frameworks/bootstrap/