The payout percentage includes both bonus payouts as well as regular wins, and the relation between the 2 could theoretically change depending on the payout setting. I would think however that the game designers would like to keep bonus game frequency pretty similar for all pay tables to preserve playability, they need to make sure the gameplay still feels palatable to the player. So maybe the bonus games happen just as often, but pay less, or the non-bonus wins pay less. They could also just decrease the frequency of the big jackpots. What you describe could be possible, but without having a copy of the PAR sheet I'm not sure that your question can be answered for sure. Keep in mind short term variance as well though. What you have been experiencing at home vs the casino could just be a fluke.