Hi,
usually the bridge rectifier before voltage divider is more precise, but in detail it depends on circuit values.
(leakage currents, stray capacitance, load resistance...)
If there is no DC component you could use a transformer. If you are not interested in DC component, then a DC blocking capacitor in series to the primary widings may be useful.
Without knowing your circuit and what´s the target value of your voltage measurement is, it´s hard to give better assistance.
Target: V_avg, V_instantaneous, V_RMS? ... and what reaction time do you need?
BTW: There are ready to buy instrumentation amplifier ICs with input voltage range beyond supply rails.
--> show us your circuit.
Klaus