HTML5 has an async attribute for script files, to enable async loading.
If you upgrade to the 1.1-alpha1 release, you can just add the async attribute to the tag format either via:
Scripts.DefaultTagFormat = @"<script src=""{0}"" async></script>"
or passing it where you want the async tag
Use following instead of Scripts.Render("~/bundles/jquery")
Scripts.RenderFormat(@"<script src=""{0}"" async></script>", "~/bundles/jquery")