Try putting $companyname in your navbits instead of {vb:raw companyname} Since it's in a single-quoted string you need to use concatenation, like:
Code:
$navbits = construct_navbits(array('' => ' </span></li><li class="navbit"><span>
<a href="/">Home</a></span></li><li class="navbit"><span>
<a href="../hostindex.php">Web Hosting</a></span></li>
<li class="navbit lastnavbit"><span>' . $companyname . '
'));