From this comparison I don't think Tottenham are the favourites but Tottenham can be unpredictable sometimes.
It is as simple as that, Arsenal are favorites based on their recent form, but in football you never know, notwithstanding they (Arsenal) have raced ahead of the other teams contending with them for the CL spot, they currently top spurs (who are closest to them in 5th place) with 4 points, and they know a win will guarantee them a place in next seasons UCL (with two games to spare), it is going to be a difficult game, but i think Arsenal can do it, even if they do not win, a draw with Spurs would be just fine and they would look to settle the whole matter in their next game against Newcastle.
From this point on i do not see how Arsenal can fail to qualify for the CL next season, except they completely capitulate and throw it all away, but that is unlikely to happen, Arteta is getting the most out of his boys, and they could be an interesting prospects in major competitions next season.