In addition to Yelp reviews for local points of interest, Maps is now showing TripAdvisor and Booking.com's hotel reviews in search results.
At this stage, Booking.com results are more prevalent than TripAdvisor for international search queries. Apple is yet to formally acknowledge the addition of these services, with its Maps attribution page currently listing Yelp as the only source for local reviews.
Apple is bolstering the amount of available on its in-house Maps service by adding new locations to the 3D Flyover feature along with bringing new local data partners on board. There's also the suggestion that the Cupertino giant is looking to introduce a Street View-style feature in Maps.