7016 is simply a low hydrogen electrode without the Fe powder additions, and the impurities that ride along with it. There is nothing inherently prohibitive when using it (as opposed to anything else that oyu may weld galv with) on galvanized except for some interference with arc stability and possible lack of fusion due to the coating, and the health issues that are always involved with welding galv.
hogan is correct, if you are doing code work you need to consider those requirements. And they vary. D1.1 implies that the galv should be removed, D1.3 considers it an essential variable.