Absolutely 100% a useful tool for bowhunting.......
I'll tell ya, I'm pretty darn good at judging yardage on the ground, but sometimes when I get 20' in a tree I just look at a landmark and can't figure out how far it is????? Things just look different in a stand......so what I do first is practice what I THINK the yardage is to landmarks, then I zip them quick with the rangefinder. Keeps me sharp and gives me concrete references.
I create a 30 yard "Circle of Death"
with my rangefinder, then find a few 20's for further reference and sort of form a mental "Bullseye" on the ground with me in the center.........when a deer passes this tree/line he's under 30.........when he reaches this tree he's 20 and so on.
Not being sure of yardages is something I don't want to add to my list of concerns while hunting.
Just like in Golf, if you are unsure of yardage or club selection your in big trouble. If you can pick the right club and know the yardage you can aim small, miss small with confidence.