It is always surprising to clients when I explain that tipping is not a tradition in most South Pacific cultures. I will speak as the Polynesians think in such locations as the Cook Islands, Samoa, Tonga, and French Polynesia, which includes Bora Bora, Moorea, and the Tuamotus Islands.
Their point of view is that the first time a person arrives into the islands, they are an “Honored” guest. One would never request a tip from an “Honored” person.
Further, let us say you are fortunate enough to return to the islands a second time. The Polynesians do not think that you would come back because of the great water, the views, or even the food. The Polynesians believe that you come back because of the people in the islands. So now you are more than an “Honored” guest you become part of the fabric of the Polynesians extended family. The Polynesians would certainly never request a family member, no matter how distantly related, to pay a tip.
We here in North America tend to want to tip, so if you do feel the need to tip, most hotel front desks have a “Christmas” box or a location to put tips. These are used collectively to benefit all.
Most hotels now offer on the room payment chits for a spa treatment or dining tip lines. You do not have to add a tip here if you do not wish. If you do feel that your service was exceptional, then a tip to this person is perfectly fine.