I'm about to book at return flight from Rome to Auckland, mixed class J & F class. The tier miles online come out as approximately 64,000.

I already have seats held through a travel agent and the projected tier miles on the skywards website is significantly less at 37,000. Both fares (online and via the agent)are the same price so assuming they are booking into the same fare class.

Can anyone please explain the difference? Are the forward projections in the skywards website not accurate? Ideally i would like to book through the agent who is going to discount the fare for me slightly, but don't want to end up with significantly less tier points.

Thanks