Master Theorem applicable here?
Yes, you can define $T'(n) = 2 T'(\frac{n}{2}) + \Theta(n \log n)$, notice that $T(n) \le T'(n)$, and use the master theorem on $T'$ to obtain an upper bound of $O(n \log^2 n)$ to $T$.

Since for $n \ge 2$, $\frac{2+\log n}{1+\log n} \le \frac{3}{2}$ you can get a better upper bound by comparing $T$ to
$$T'' = \begin{cases}\frac{3}{2}T''(\frac{n}{2}) + \Theta(n \log n) &amp; \text{if $n\ge2$} \\ \Theta(1) &amp; \text{otherwise}\end{cases}.$$ Applying the master theorem on $T''$ yields and upper bound of $O(n \log n)$ for $T$.