Generally, the tolerance refers to how close the actual capacitance is vs that stated. In this case, the 100uF capacitor with +/- 10% could have a capacitance from 90uF to 110uF.
This is quite separate from the voltage the capacitor is rated at - this measures (roughly) at what voltage the dielectric that separates the plates will break down and let current flow directly them.
Therefore, you need to understand the reason you have a capacitor in that place in your circuit. If it were part of a tuned circuit (for example), then the resonant frequency will be directly related to the capacitance and so you may want the smallest tolerance possible. In your case it looks as though these are only being used as smoothing capacitors in the output of the PSU so the exact value is of lesser concern. On the other hand, you had better get the voltage tolerance well above the output voltage or you will be in big trouble.
Susan