I found my answer here: https://solana.stackexchange.com/questions/8549/how-to-getprogramaccounts-for-token-2022-program

Plus this helped with a more simplified set of code to follow: https://www.quicknode.com/guides/solana-development/spl-tokens/how-to-get-all-tokens-held-by-a-wallet-in-solana

Turns out that ai16z tokens are part of the 2022 token program so must be looked up in a different manner.