He was referring to Ichigo prior, but what we're shown with Ichigo don't reflect that statement. He never touches his hand.
It instead matches Renji. After Tenjirou punches him in the gut, there's a giant splash in the water and yet he's still standing there, cockily asking how wasn't he sent flying away. He then notices Renji's hand trembling. Combined with Tenjirou's statement, it'd seem like Renji was sent flying into the water, but immediately flash stepped back to the fist.
I wouldn't put Zaraki as stronger than Shunsui, at least not in his current state.