For a steak I'd say about 5 minutes should do it. I simply tent versus wrapping. Unless you are under cooking your meat I would be afraid wrapping would cause my steak to overcook. And yes, as Wyogal stated, it allows the juices to basically sink back into the meat (steak, chicken, smoked pork butt, brisket, etc.). While it's cooking all those juices are moving around and rise to the surface. If you cut a piece of meat immediately after removing from the heat source the juices simply spill out of the meat and what's left is a piece of meat with no juices left in it. Resting makes a HUGE difference.
Even grilled meats need to rest.
Going from grill to plate is fine, just don't cut it! If someone served me a steak right off the grill I would let it rest on my plate and no one would be the wiser...except my tastebuds!