Can I $.wrap() around a collection of elements in an array?

Answer 1

Try wrapAll method instead:

$(".group").wrapAll("
");

DEMO: http://jsfiddle.net/LanMt/3/

---

For wrapping the separate groups of .group elements you can use the following:

$(".group").map(function() {
    if (!$(this).prev().hasClass("group")) {
        return $(this).nextUntil(":not(.group)").andSelf();
    }
}).wrap("
");

DEMO: http://jsfiddle.net/LanMt/5/

The code above was assembled with the help of @Jon's answer.