personally i think it's best to not mix oil and water based compounds in the same syringe for obvious reasons. My friend used to get sick with nausia every time he did this but not when he kept the water and oil injections separate.
OK, this one had some merit, but it's really just common sense. First thing I'd consider is, which of these vials is a multi-vial, e.g., has more than one dose. If you have amps of winny and 10ml bottles of test, then draw the test first, then the winny (so as to have the least chance of contaminating any multi-use vial). This is a personal, paranoide preference. As far as the second thing to consider is how thick things are. Are you using a drawing needle? I'd recommend using an 18g drawing needle with that Winny. Just think about it, consider what you have, and do what makes sense. Definitely don't get any of the water-based compound mixed into an oil-based multi-use vial, though.
-B