This should be done with JavaScript. Create two div's. One with the mobile link to the profile and one that tells the user to open the site on their iOS Device. Then use JavaScript to show/hide them as necessary.
<script>
var iOS = ( navigator.userAgent.match(/(iPad|iPhone|iPod)/g) ? true : false );
if (iOS) {
document.getElementById("ifiOSHiddenDIV").style.display="true";
}
</script>
<!-- HTML-->
<div id="ifiOSHiddenDIV" />
Link to Mobile Provision
</div>
These links will also help:
Detect if device is iOS
Hide an html element using javascript only if browser is firefox