I would like to find out what my allies need, so I can gift it to them. Is there an easy way to find out what they might be longing for at this particular time?
One option would be to put something on the table and ask "What would you give me for this?" You will then get an idea of how the AI evaluates that which you are offering. Keep in mind that other factors, including your relationship, will influence this as well.
I'm not sure how the AI evaluates it's own gratitude, so you'll have to experiment a bit to see if this works.