you will possibly need to add some CSS class to the link html code of the logo code, and apply some CSS to get it centered;
example:
<a class="footer-logo" href="http://www.stylelist.com/"><img src="http://o.aolcdn.com/os/Stylelist/images/network_stylelist_blackonwhite.jpg"></a>
and:
.footer-logo { display: block; margin: auto; text-align: center; }
please post any further theme related questions at http://wordpress.org/support/theme/striker/