Yea that's probably an example - those companies get preferential treatment on the network w.r.t traffic and so competitors have a harder time entering the market.
If you're on the top plan then you haven't experienced it. The irony is that T-Mobile was one of the ISPs throwing support behind net-neutrality, and now they are one of the most aggressive net discriminators.
I don’t think bundling other paid services counts. It’s only if the ISP treats the traffic to/from those paid services differently that you run afoul of net neutrality.
TMobile gives me free Netflix, but I use it on my television which uses my home internet. So even if they zero-rated that service, in my case it's irrelevant.
Plus I think I have an unlimited* plan, so zero-rating something doesn't have much impact.