Curious on your baggage issues? What reason did they provide for not putting it all on 1 ticket/reservation? How did you book your flights?
As I posted, Fiji Airlines put my entire itinerary on 1 e-ticket/reservation so the baggage allowances are identical for all segments (international and domestic). I booked directly with Fiji Airlines.
I know this question wasn't for me, but I can give you my perspective as someone that was just there and traveled with 16 others from various parts of the USA and all went about booking our flights independently.
I booked my flight through Alaska Airlines using my Alaska Airlines frequent flier miles. They are a partner with Fiji Airways. That free flight only got me as far as Nadi (Portland to San Fransico to Nadi) - round trip. I had to book a separate flight from Nadi to Taveuni with Fiji Airways and I had to pay for it separately. I had researched enough to know that the commuter flight from Nadi to Taveuni on Fiji Link (codeshare partner of Fiji Airways) has very strict baggage allowances and baggage fees. The planes are tiny and not only is every bag weighed (checked or carry-on), but you are also put on a scale to make sure the plane is not overloaded. And they are particular about where each person sits on the plane to balance out the weight. Strict limits on checked and carry-on luggage (number of pieces and weight of each piece).
You can prepay for extra baggage ahead of time online (although that wasn't particularly easy), but it is much less expensive and you need to know and read the fine print to pack things wisely. If you show up and haven't pre-paid and don't have things sorted properly, you can end up paying excessive baggage fees.
Others in my group, booked everything directly with Fiji Airways from the jump and their baggage allowances on the flight from San Francisco or Los Angeles were carried over to the commuter flight to Nadi and had zero issues with baggage fees and were never questioned about anything.
Others in my group also used frequent flier miles and booked the 2 flights separately, but didn't know about the baggage allowances and paid much more than I did, because they didn't pre-pay. Others booked the 2 flights separately and didn't pre-pay for baggage and no one said a thing and they skated through based on who they checked in with.
Also, if you are flying 1st class, business class or economy will also play a factor.
Bottom line is-- you should be good since you booked everything through Fiji Airways directly. Others should do some research.