If you're going to use Grunt for bundling and minification, then I don't think you need to use ASP.NET Web Optimization framework. Why to use both? Just insert links to your bundled app.css and app.js files on your page and you're all set. You can also use @if ... statements to include different versions of your files (development vs production).
Also, take a look at Gulp.js - a newer alternative to Grunt, and this project template, which already has some basic Gulp.js configuration in place: ASP.NET Solution Template
A couple of Gulp.js plugins which can help with a CDN:
- gulp-s3 - Uploads your static files to Amazon S3 during a build
- gulp-google-cdn - Replaces references to 3rd party libraries with Gogole CDN links
After Gulp.js is configured via gulpfile.js file, you can run:
gulp build --production
..in order to build your HTML/LESS/JS files and publish them to Amazon S3 or some other CDN.