Samsung Galaxy Smartwatch IPhone AT&T LTE compatibly

Has anyone successfully paired a Samsung galaxy smartwatch with an IPhone 6s or 7 and used AT&T LTE service?  I have seen reviews indicating such (they did not specifically include the LTE), but am now being told they are incompatible. I wonder if it is a lack of knowledge on upgrades, or if it is factual... will their be a software upgrade in the future to address the issue.