I just donated twice in a row to a Pot shrine, the first time was 2 music blocks and the second was 1 music block (I don't remember which ones specifically). Here are the messages I got:
You donated to a Shring to Pot. Your favor with Pot has increased by 80! You gain 192 xp and gain 5 mood.
You donated to a Shrine to Pot. Your favor with Pot has increased by 50! You gain 2620 xp and gain 1000 mood.
That second one seems a little bit off :) Though now that I'm noticing that my mood isn't full, I don't think I actually got all the xp and mood boost..