Who's your mobile provider? We have T-Mobile, which covers slow data for free in French Polynesia, and one has the option of purchasing an international data pass for high speed data. I know other providers have similar plans. I considered briefly getting a SIM card, but I decided against it since, like you, we were at the Hilton and the Conrad for most of our time there.

There are also mobile hotspot rentals available from the vendors nearby the rental car stands landside, but I didn't investigate pricing. Wi-Fi coverage at the Hilton and Conrad are both good throughout the properties.