[OS X TeX] Vertical Spacing in "bmatrix" environment

[Hendrik]

Folks,

I'm using the "\begin{bmatrix} \end{bmatrix}" enviroment from AMSmath.
The following is part of the tex source.

\begin{bmatrix}
    \frac{s+5}{s^2+5s+4} \\
    \frac{-1}({s^2+5s+4}
\end{bmatrix}

Since the elements I put in the matrix are all rational polynominals, each 
row seemed to stack on each other.  Is there a way to increase the spacing 
between rows?

My current solution is to put element in \scriptstyle which essentially uses 
smaller font size.

Cheers,
Hendrik