I have tested SRS circuits in the past in an attempt to find out what exactly goes on. The voltage between the lamp electrodes during startup measures at around 270-280V. Whether this is due to resonance, or the fact that the voltage between the two coils is out of phase I don't know, but there is certainly a voltage boost.
If you disconnect the power to the circuit before the lamp has struck, the voltage across the lamp persists for around half a second, reducing slowly. This can be seen as a continuing glow discharge in the lamp that fades away.