As I understand it, the first English colonies in present day United States were founded by royal charters given to colonial companies - The London company which founded Jamestown and the Plymouth Company which founded the Massachusetts Bay colony among them. The land belonged to the Crown and the companies were essentially tenants.
However, in 1681 Charles II gave Pennsylvania to William Penn to settle a debt owed to his father, and even insisted on the name despite Penn's dislike for it. As far as I know Pennsylvania was the only colony founded as a grant to a single person instead of a company - why the change in policy? Also, how did Charles II envision Pennsylvania? To me it seems like a fief, granted to a single person. Was this the plan for further lands in America?
Minor correction: Maryland was also founded as a grant to a single person, and this was prior to the grant to Penn for Pennsylvania (20 June 1632 for Maryland and 28 February 1681 for Pennsylvania). George Calvert was originally the intended governor, but he died just before the charter was created. His son Cecil Calvert received the proprietorship instead. They were the first and second Barons of Baltimore (of the Baltimore Manor in Ireland, not the city in Maryland, which was named after the Port of Baltimore, which was in turn named after Cecil Calvert himself after his death).
Still leaves your question unanswered - but if there was a "change in policy" as you said, it happened much earlier.
I would also like to know how much power a royal charter would give the founders of a colony?