PCR ZZ01 would transfer the values of WT 9YY1 into Temporary Variable 9YY1 (but there must be no space between ADDWT& and 9YY1), but WT 9YY1 will disappear from the Input Table unless you also use ADDWT *.
PCR ZZ02 implies that WT 9YY1 would hold a Number, but you need a space between NUM=& and 9YY1. Otherwise, it looks good.
Since you mentioned that the Bonus is usually only in December, a WT on IT0015 would have only one validity date, while an IT0014 is usually for Recurring Payments.
A PCR that is called by function PORT will enable you to retrieve information from the previous Payroll Period and save it either in the Input Table or in a Temporary Variable, but it can't process both teh Old Results Table and the Input Table at the same time.
You must place ZZ01 after Functions P0014 (or P0015) because WT 9YY1 does not exist in the Input Table before then, and it must be placed before WT 9YY1 "disappears" from the Input Table or is transfered to the Results Table (RT).
You must place ZZ02 after ZZ01.