Domestically, the money could be coming from donations to Advance NZ and the Outdoors Party / Sue Greys legal fees to clients. They have all been involved as far as I know. Another prominent person involved with the distribution of the pamphlets is Claire Deeks, I assume she will have some money from MLM sales.
I wouldn't be surprised if there was international money or coordination behind it though:
David Farrier and co report on Bannon's NZ media
Graphika report on Bannon's worldwide media (features NZ)
His media empire pushes anti vax conspiracies and anti CCP stuff while also targetting anti CCP Chinese activists, while promoting a "New Federal State of China"
No ties directly to pamphlets that I have seen but he has had Jamie Lee Ross (Advance NZ) and Elliot Ikilei (New Conservatives) on his show.