Green Mountain Inn near Stowe is Vail owned but no option to book on the Epic app?

On the app, there are only options for Hunter, Mount Snow and Okemo to book hotels at for the 20% discount. I’m trying to find a place to stay for a couple nights next week. I read good things about The Green Mountain and that Epic pass gets you a 20% discount. I guess you have to call the hotel itself? Weird that if they are actually owned by Vail, it’s not advertised on the app.

Also, wondering what other Vail owned hotels in the north east I could be getting 20% off of that I’m not aware of.