A26 Samsung phone - S8 46MM watch

Anyone have any experience with Samsung Watch without 2nd line ($10/mo discounted price)?

I want the S8 watch but with Comcast (USA), I am getting mixed response in-person and no clear chatbot/assistance.  I want to use the watch and not opposed to tethering the mobile data usage when out of range (just like my phone).    Hence on salesperson would sell watch without 2nd line while the other sales associate would not. 

I want the S8 watch with Wi-Fi, Blue Tooth and Mobile Tethering support, not an additional line.  One Comcast Sales Associate and a very knowledgeable technical lead having transferred from mobile engineering, said yes.

After activation, of phone and purchase of protective case (ignorantly of protective case with wireless charging magnetic component), I went to store to purchase watch where the 2nd sales associate said they could only sell with addition of mobile line.  

FYI, while the watch and phone are great prices, the $10/month makes this a lousy option i.e. a $7,200 option over typical life of watch.