There are quite a few other benefits with the WiFi... that supposedly will enhance the experience e.g. apps that describe on filed statistics. etc. As a reference point, check out Levi's Stadium -home of the SF 49:ers and what Accenture did in collaboration with 6 nations in Rugby.
Worth pointing out, I have never been to that stadium nor have I used that 6 nation app. I have only read about it. Personally, I prefer to watch the game and have a pint before, in the middle. and after the game
Main wifi benefit I can think of apart from betting is replays. i think Wembley trailed the software/app at the play off final.