Given a choice, I'd go for one of the same capacitance (47µF) and higher voltage. The capacitance may be important to the function of the circuit as it will affect things like resonant frequencies.
That said, a relatively-high-value (probably electrolytic) capacitor like this is likely to be used for power supply decoupling or smoothing rather than in an oscillator or filter so a higher value should be OK.
Stephen