The Event Hotel has its own in-app boosters (VIP pack and Boosters 1, 2, and 3) which are different from the purchases in your regular hotels because they are designed for the event mechanics. Since each event offers a different reward, each event will have its own purchases. This means, the event purchases are only valid in the current event.

No-ads will work during the whole game in all your hotels, including all events.
Marketing Expert and General Manager will work forever in all your permanent hotels, but they won't in the weekly Event Hotel.