Here is a quick and dirty way: You could use dict comprehension to set a 'to' field from a list. I assume the other fields are the same for all payouts, then you can do something like:

list_of_recipients = ['user1', 'user2', 'user3']
transaction_template = {'from':'user0', ... }

transactions = [transactions.Transfer(**{**transaction_template, 'to': x}) for x in list_of_recipients]