Arsenal's win at Stamford Bridge was their eighth in nine matches and it lifted them up to within three points of the top four.
But van der Vaart, who helped Spurs extend their unbeaten run to seven in Sunday's 3-1 win over QPR, claimed: "We are better than Arsenal.
"In our last seven games we have won six and drawn once. It's a long season, but I think we have a bigger and better squad."
Chelsea and Arsenal have dominated the London scene for the last two decades, but under Harry Redknapp, Tottenham reached the Champions League quarter-finals last term, and look set to challenge for qualification to Europe's top club competition again this term.
Sunday's win, which came courtesy of a van der Vaart goal and a double from Gareth Bale, moved Spurs level on points with Chelsea, who are stuck in third after losing their last two games.
Van der Vaart is so confident about Spurs' strength in depth that he thinks the club could challenge the likes of Chelsea and even Manchester United for second and third place come the end of the season behind Manchester City.
"Are we the best team in London? Maybe, but it's still early," the Holland midfielder said.
"We're in a good way. We are much better than we were last season.
"Man City is the best team in the league and below them you have a lot of good teams and we are one of them."
Van der Vaart has been impressed with City's performances this year - they beat Tottenham 5-1 at White Hart Lane in August - although he does think the wheels could come off their title assault at any point due to the big egos in the City dressing room.
"At the moment they are really good. They are winning games easily and how they played against Man United was impressive, but they also have the difficulty of a lot of egos so that could also be a problem," the 28-year-old said.
"When you play for a big team, when they buy a lot of good players and a lot of players also aren't happy.
"Look at (Emmanuel) Adebayor. He is a great player for us, but he was not even in the squad at City and was training with the youngsters."
Source: AFP
Source: AFP