They should already see the 'via' user as a suugested follower- if it's not YOU tweeting since you can't follow yourself... you can add an additional suggested follow by adding:
Code:
data-related="2ndUSERNAME"
to the twitter code, so:
Code:
<a href="http://twitter.com/share" class="twitter-share-button" data-count="horizontal" data-via="YOUR_TWITTER_USERNAME" data-related="2ndUSERNAME">Tweet</a><script type="text/javascript" src="http://platform.twitter.com/widgets.js"></script>