Manchester United hitman is happy that six points were taken from the two games, and delighted to see younger generation of players impressing at senior level for the Three Lions
The Three Lions now have a six-point lead at the top of Group G, albeit having played a game more than second-placed Montenegro.
Fabio Capello's side now need a draw in next month's away clash against Montenegro to ensure a place in Poland and Ukraine.
"It's a nice to get the six points and more or less have one foot in the finals," Rooney said following the 1-0 victory over Wales at Wembley on Tuesday.
"It was a tad frustrating at times but the result was the most important thing and we're thankful for that."
The visitors put in a strong performance following their win over Montenegro, and could have carved out a draw had Robert Earnshaw not missed a sitter.
"They did [take us by surprise], to be honest - they played really well," said the Manchester United forward.
"Thankfully, we held on towards the end to get the win. We weren't at our best."
Despite the relatively subdued performance against Wales compared to the emphatic 3-0 victory over Bulgaria in Sofia, Rooney was happy to see the younger generation being introduced into the squad.
"It's nice, obviously, for the young players to get their chance and they've all done well when they have done," he said. "It's obviously great for the future for England."