Yup. I used a ATT Gear S with my Note 2, am currently using a Verizon Gear S2 with no plan paired with my Note 4.
Slightly off topic, but, have you gotten Samsung Pay to work on your Gear S2 and successfully added a debit/credit card? I'm using an AT&T S2 3G paired to my Note 4, but I'm not on AT&T, so the watch is just functioning as a bluetooth-paired device. But, I can't add a card to Samsung Pay.