He and John have a complex relationship. Everyone looks down on Jamie, though he has done, literally everything John has asked of him. John doesn't seem to hold any love for Jamie, and often acts as though he will ruin the ranch with zero shown evidence so far to back that theory up.
Before he was Jamie Dutton, his name was Michael Randall. As an infant, he lived in the household of Garrett and Phyllis Randall. His mother was a junkie and his father was working to make ends meet. One day, Garrett walked in on his wife whoring herself off to some stranger while Jamie was crying because he was hungry and was sucking on some crack pipe. Infuriated, Garrett murdered his wife in order to save his child from the life he was living. He spent more than 3 decades in prison for the murder and Jamie was adopted by John and Evelyn Dutton. As a teen, he helped cover up a teenage pregnancy by taking Bethany to an abortion clinic in a rural part of Montana, to avoid anyone seeing a Dutton in a clinic in a high populated place like Bozeman.