I can find for transaction records how to report on the system notes but I do not see a way to find the system notes for either the item or expense line items on transactions like vendor bills. Is there no audit records for changes on the sublists?

For a transaction search, use "Line System Notes fields" if you're looking for the system notes for the lines on the transaction.

I was having an issue with getting a search object built to pull it, kept coming up empty. Finally resorted to the saved search to script chrome extension and I have it working now, thanks