So clearly, if you are giving non-discretionary bonuses based upon production standards, the amount of the bonuses or the value of the award must be added to the base pay rate of the employee and then overtime must be calculated on this amount. If you fail to do so you run the risk of falling into the same trap that caught QuikTrip and many others. Go back and read the comments from yesterday, they are very informative.
As additional resources on this topic see also Ann Bares post on Compensation Force entitled
Know Ye the Regs When Awarding Bonuses or Lump Sums to Nonexempts and Michael Moore's post entitled Bonus and other Lump Sum Payments to Nonexempt Employees may Impact Overtime Calculations . Both are very informative.