If you mean for the same transformer primary-to-secondary ratio but with the center tap used in one case (with 2 diodes) and with the the total winding used in the other (with 4 diodes in a bridge configuration) - then yes that's true. In the first case only half the total secondary voltage is rectified on each half cycle whereas in the latter case the full secondary voltage is rectified on each half cycle of the mains waveform. If the CT case had a different transformer with a total secondary voltage twice that of the other, then the result would be the same - ignoring the diode voltage drops.