There are a number of different ways in which to answer this question.
First, we can compare these two teams in terms of their payroll. It is generally the case that teams with larger payrolls have better chances of winning. If this is the case, the Yankees are far better-off than the Blue Jays. The Blue Jays are above average in terms of salary. They are 11th in the league with a payroll of $115 million this year. However, the Yankees have the second highest payroll in MLB with $210 million. This is a big difference.
Second, we can look at things in terms of expectations. The Yankees do have a huge payroll, but all is not well with them. They have a tremendous amount of money committed to Alex Rodriguez, whose future is unclear due to health issues and the issue of performance enhancing drugs. They are an old team with stars like Rodriguez, Derek Jeter, and Mariano Rivera. From this perspective, the Blue Jays actually seem to some like a better bet to win. The link below predicts that the Blue Jays will finish ahead of the Yankees in the AL East this year.
So, it is, of course, hard to say how the two compare. That’s one of the great things about sports. We just have to wait and see.