If by "bubble" they mean companies that aren't profitable are being valued at enormous amounts, and continue to garner investment even without any clear revenue

If by "bubble" they mean companies that aren't profitable are being valued at enormous amounts, and continue to garner investment even without any clear revenue or exit strategy, then yes we are in a bubble. The problem is the web industry considers investment to be revenue... in which case you're never in a bubble because profit doesn't really matter. Success in the web industry is simply getting someone to throw money at you.