I don't know about Ireland specifically, but in most places bonusses are taxed in the tax year he are paid. (money.stackexchange.com)
so it can not really mean to much even if true since most often those items do provide bonusses over other items even if only in the beginning. (kickstarter.com)
One thing that the publsher's apologists forgot to mention is that they have to charge more so that they can pay huge salaries and bonusses to their top executives... (gigaom.com)