In most contracts the data used for the "special" apps do not count against your bandwidth plan. Here's a T-Mobile example that has several "special" services that don't add to your bandwidth.

There are multiple tiers of bandwidth I can get exclusively for video sites with my phone plan. non video sites aren’t throttled under any plan, but YouTube, Netflix, etc are depending on what tier you pay for. The people I know who pay for the top plans get access to the offered streaming service with priority bandwidth.