Real doubtful. Some of the most thorough tests are life insurance tests - many even test your urine (or is it blood - can't remember) for traces of cigarette smoke even if you say you are not a cigarette smoker. Its not cost effective to test for a drug like Deca which is used/abused by such a small part of the population and even if abused causes no significant liability risk to an employer - unlike alcohol or cocaine which can significantly impair an employees ability to work, drive a truck etc.
If they do test you could not claim HRT. MD's don't prescribe deca or winny for HRT except maybe for Dr. Scruggs. You could claim norandro (OTC vitamin supplment) as the cuase of deca coming up positive. I am not sure what you could claim for winny.
If you are doing winny and they do a cholesterol test or blood test looking at liver enzymes then they might come out all messed up because winny does a number on your liver and your cholesterol - but they won't know its due to AS use. They would just think you have screwed up cholesterol and perhaps drink too much alcohol or take too much Tylenol.
If its just a urine test its real real real unlikley that they are testing for AS for an employment screening.