If you add items to a listview, you'll need to call the refresh() method on it to update the styles and create any nested lists that are added. For example:
$('#mylist').listview('refresh');
What code I need if I add buttons to the page and refresh the style.
This one:
$('buttonID').button();
Working example: http://jsfiddle.net/Gajotres/m4rjZ/
There's also another function called buttonMarkup(), it is used to change some already styled button properties, for example to change button icon:
$('buttonID').buttonMarkup({ icon: "star" });
Read more about it in my other article: jQuery Mobile: Markup Enhancement of dynamically added content
And a link to an official documentation.