In order to track clicks in html banner, use {{tm_banner_url}}
variable for all links:
<a href="{{tm_banner_url}}" title="Trackable Link">Click Me!</a>
You can also track clicks on link with ajax request:
<a id="link-id" href="tel:555" title="Call us">Call us</a>
<script>
$('link-id').observe('click', function(e) {
new Ajax.Request('{{tm_banner_url}}');
});
</script>