By "neighbors", do mean destinations like Australia and New Zealand? Again, you are making signficant assumptions here which can easily be disproved by the fare filings found on ExpertFlyer.com. I've copied the first couple dozen or so FJ fare filings on NAN-AKL. Presumably, you are talking about upfaring from a Lite fare to Value fare? The cheapest fares on route below are RLTFJN80 fares which are R fares which earn nothing. These are "Lite" fares as identified by the "LT" in second and third letters of fare basis codes. If you upfare this fare to a "Value" fare, it will have fare basis code RVLFJN80 which is still an R fare and earns nothing. You can tell it's a Value by the "VL" in the second and third letters of fare basis codes. Upfaring to a "Comfort" fare will get you a RCMFJN80 fare which is still an R fare (letters "CM" in fare basis code). And finally, the corresponding "Plus" fare which is RPLFJN80 and still an R fare (letters "PL" in fare basis code). These are what is known as "branded" fare products where you can have multiple types of experiences which all book into the same booking class.

The next fare filing up is a TLTFJN80 fare which again a "Lite" fare that books in T class and will earn 35% mileage flown. The TVLFNJ80 "Value" upfare for this fare is also still just a T fare. And so on. Hopefully, you are maybe getting the idea now.