Just noticed NowTV have recently updated their Sports Pass Help Article, where this is now mentioned under the FAQ sub heading " Can i Watch Bonus Streams and use other Red Button or interactive service on NowTV".
Here's the section copied and pasted below.
If you've got a Sky Sports Month Pass and one of the devices listed below, you can access Bonus Streams for selected sports events, including additional EFL matches and F1 Race Control.
When a Bonus Stream is available, you'll find the option at the bottom of your NOW TV app homepage.
Keep in mindYou can't watch Bonus Streams with a Sky Sports Day, Week or Mobile Month Pass.
Bonus Streams will be coming to the NOW TV Smart Stick and Boxes (except the white NOW TV Box) later this year.
When a link is blue and underlined, and not an @name, you can press or click it to dig deeper.
You will find such a link in @schnapps original posting in this thread, in which link the name LG is not absent.
I noticed these Bonus channels popping up on my Samsung TV (though possibly from my YouView box, not the TV itself - I don’t recall) during last week’s F1, about six of them. Though as I wasn’t rocking a suitable Sports Pass, I couldn’t actually open any of them.
If your Samsung Smart TV supports Bonus Sports Streams then they are usually found on the bottom of the NowTV front end home page screen.
Bonus Streams are not there full time and usually pop up when there is a F1 Race or Championship Football which so far is the only time that i have noticed them on my Youview Box.