Adding to the accepted answer, when working within containers and columns that have built in padding from bootstrap, I sometimes have a full stretched column with a child div that does the pulling to be the way to go.
<div class="row">
<div class="col-sm-12">
<div class="pull-right">
<p>I am right aligned, factoring in container column padding</p>
</div>
</div>
</div>
Alternately, have all your columns add up to your total number of grid columns (12 by default) along with having the first column be offset.
<div class="row">
<div class="col-sm-4 col-sm-offset-4">
This content and its sibling..
</div>
<div class="col-sm-4">
are right aligned as a whole thanks to the offset on the first column and the sum of the columns used is the total available (12).
</div>
</div>