You may be better off concentrating on using points for the airline tix. I would guess that most of the overwater villas are either not available using points or very limited and prohibitively expensive. I just looked at Hilton and they quoted 172k-192k pts per night, but I didn't see any availability for 5 nights over the next 10 months.

The $99 AS companion ticket can only be used on AS flights and I'm pretty sure they don't fly to Tahiti. Did you mean that you could use it to get to/from Hawaii which might make the trip to Tahiti a little easier/cheaper? You may want to look into trying to get SkyTeam award tix, esp on Air France. Generally, using DL Skymiles would be the way to go, but there's a lot of rumors about upcoming major changes to their program. They may devalue the points before you can get enough to book the tickets. Another option would be to start collecting Amex Membership Rewards points which could be transferred to DL or other airlines including directly to Air France (although they have big fuel surcharges) when the time came.

Have fun planning your honeymoon. My wife and I spent a week in Tahiti a while ago at the Club Meds in Bora Bora (overwater villas or fares) and Moorea. It was a magical trip.