Oh yeah! There are a LOT of similarities and we love them.
See, shooting a bow is GREAT for slingshot shooters and shooting a slingshot is GREAT for archers!
Both disciplines require muscle training (especially those stabilizing muscles). But while shooting a bow requires frequent trips down range to retrieve arrows and a full weight draw, slingshot shooters can reel off several hundred shots (with a lighter draw and no need to retrieve shots).
Slingshot shooting is OUTSTANDING practice for all our archers out there! Try it out and see if it doesn't massively improve your archery skills!