I believe there are no 20% bonus here. I mined in the "classic" pools and in this p2p pool. I saw no difference, I've got the same amount of coins in 24 hrs.
you are a very negative person since you started popping up here... i've just been testing out mining at this pool and if i look in my wallet i have 2 payouts, one of 190 karma and one straight away of 38 karma.. and guess what 20% of 190 is 38 so the 20% payout is working
Now... the bonuses do not exactly match up to block rewards, in the newest block someone mines 11954.18750638 but is paid 2424.07006247 instead of exactly 2390.837501276. The reason for this small discrepancy is because the donation script runs once a minute and the payout may have changed slightly from when the block was found.
I don't know what else to say. Crocko post a link to one of the blocks you mined on p2pool where you did not get your bonus.
Someone also asked about the "Stratum from pool 0 requested work restart". It's because p2pool runs its own internal blockchain that is faster than the karma blockchain. It has no impact on your mining at all. You will still see the same amount of coins.