I believe early entry via a partner hotel is only if you book a pakage though Universal's site for one of the partner hotels.
When I look at this page below it only mentions Early entry as a bonus if you book a package
https://www.universalorlando.com/web/en/us/tickets-packages/vacation-packages/partner-hotel-packages
When just booking one of the hotels it only mentions the following:
A VARIETY OF HOTEL OPTIONS MINUTES AWAY.
Chosen based on quality, reputation, and proximity to Universal Orlando Resort, the Universal Partner Hotels are each located within minutes of Universal Orlando. From value to moderate to luxury accommodations, Universal Partner Hotels offer many ideal options. Plus, you’ll receive FREE scheduled transportation* between your hotel and Universal Orlando. In addition to transportation and the wide range of accommodations Universal Partner Hotels offer, guests can also enjoy additional BONUS BENEFITS** at most of the partner hotels.
Guests staying at most participating partner hotels receive the following Bonus Benefits:
- Discounts on merchandise at select Universal Orlando theme park locations
- Discounts on food and non-alcoholic beverages at select theme park and CityWalk locations.
- Universal Partner Hotel Vacation Planning Center