A 41-16 victory in Sydney sealed the series and Farrell insists the northern hemisphere can take great pride and confidence from that performance.
"There will be massive benefits, a huge carry-over," Farrell told the Telegraph.
"We had a three-day training camp with England and even though the Lions boys were not fully training, it was obvious that those involved had learned shed-loads.
"It has blown away our lads. It is exactly what we wanted - those insights, that level of confidence derived from it. The aim is for these lads - such as Alex Corbisiero, Tom and Ben Youngs among others - to move on to world-class level.
"In a national squad you need everyone to be pushing to get better. The young Lions lads now know what it takes
"Given that people felt that the momentum had shifted to the Aussies after the loss in the second Test, that third Test became the pressure game, a winner-takes-all, a World Cup final. And the northern hemisphere lads did us proud didn't they, they came up with the goods.
"They didn't just win, they dominated. They dealt with that pressure and showed how mentally tough they are. It was the biggest game of their lives for many of them. That's a big, big marker to lay down."
Two English players started the third Test in Alex Corbisiero and Parling but five additional Red Rose stars came off the bench.
And Rowntree insists the motivation is now there for his international side to press claims for a starting berth in the 2017 tour to New Zealand.
"Our lads go on a Lions tour, and you've got [lock] Geoff Parling rubbing shoulders with Alun Wyn Jones, [prop] Dan Cole with Adam Jones," he added.
"And our boys see how diligent others are. They do their homework. Off the field, analysis, training, it is all so important.
"They were disappointed, the likes of Tom Croft, Ben Youngs, Dan Cole, but they knew why they weren't starting. They have to absorb it and use it."