The Prime Minister did not ask whether the National Security Agency (NSA) may have spied or held information on New Zealanders, and said he was comfortable with the way that the spy agency operated.
Mr Key said the president broadly shared New Zealand's view on the TPP.
"We can all see the challenges that are there, but we can also both see very much the prize that lies in wait of countries if they sign up.
"I think we'll get a sense in the first half of this year ... whether it's a goer or not. We've had numerous meetings now and we are starting to get to the point where it's crunch time.''
Asked whether he still needed to visit the White House after having such a comprehensive discussion with the president, he said: "At the end of the day ... we probably had a decade of bilaterals in one golf game ... but because there's so many areas where we engage with the Americans, where we have such a deep history with the country I think it's a good thing if we can get that formal meeting.''
He said that he gave his foreign policy advisor a briefing of what he had discussed after the game.
Mr Key said he and Mr Obama played as a team, and beat his son Max, who formed a team with a presidential aide.
He would not reveal the score, only saying: "We won.''
Asked whether he was advised about any protocols for playing golf with the president, he joked: "Don't steal his ball.''