Is it a notification that the phone is connected to wifi, or that the watch is using wifi?
I've never seen a wifi notification on my Urbane that's connected to my Note 4.
That's strange. Mine never does that. I wonder if it's because of a difference in how Samsung & LG handle that notification.
You'd think there'd be a way to turn it off though.
Can you take a screenshot or a picture & show us exactly what it looks like?