Half columns in Twitter Bootstrap 3
You can try this :
Just split a col-9 in 2 parts.
Bootply : http://www.bootply.com/128927
HTML :
<div class="col-xs-3"> col-xs-3 </div>
<div class="col-xs-9">
<div class="row">
<div class="col-xs-6">col-xs-4.5</div>
<div class="col-xs-6">col-xs-4.5 </div>
</div>
</div>