If I rephrased the question like this, would it still be accurate?
"I have a Welding Procedure Specification that was qualified using a groove-weld test. Can I use this Welding Procedure Specification for fillet welds on all thicknesses of base material, on all diameters of pipe?"
If that is a similar question, I would take a look at QW-202.2(c) Qualification of Fillet Welds.
It is important to know the basis if you are allowing work to be performed using that WPS, but the short answer is no, you don't have any limits for thickness or diameter for fillet welds.
-Erik