so when you shoot enderman they are supposed to teleport away and not get hit by arrows but if the arrows are tipped they will still leave the potion effect on the enderman. this can be most clearly seen if you shoot an enderman with an and spectral invisibility tipped arrow.
Note : instant damage 2 tipped arrow doesn't seem to effect it
tested arrrows that work:spectral,invisability,poison,fire resistance,speed...