Bookings have been going up and down the last decade and are watched closely by the industry in general. Weather and snow conditions impact those numbers more than anything else. There are many Epic pass holders who don't stay in VR lodging, especially in CO, UT, Tahoe. Plenty of alternatives to expensive slopeside lodging owned/operated by VR.
What investors watch is the number of Epic passes and the revenue change for Epic passes over time. VR stated that 75% of the people at Epic resorts are using some type of Epic pass, including the Epic Day Pass (1-7 days).
Alterra's business model for how a resort is operated is quite different than the fully centralized approached used by VR. Look at a few resort websites. For instance, for Epic resorts the home page is clearly using the same framework. The look for PA resorts and Park City is similar. That's not the case for Alterra resorts. Compare the websites for Mammoth and Solitude. See if you get the impression from the homepage that they are owned by the same company.