I know you can go to the main island, but you have to pay for a boat transfer. Pre-covid you can pay for boat transfers to other resorts, when we went in November 2020, you can only go to the mainland. In all honesty, visiting restaurants in the mainland were pretty mediocre and not worth the cost or trouble. Unless you're eager to see what other resorts are like, restaurants there are about the same as StR. The Jean Georges restaurant on site is by far the best restaurant amongst all the properties, at least in comparison to the Intercontinental and FS. Didn't visit the Conrad as the boat transfer was way more expensive than to the other properties