All true; Bergson's critique is believed to have directly influenced the Nobel prize committee. In hindsight an absolute travesty.
However, I would not say that Einstein's explanation of the photoelectric effect was not Nobel prize worthy in itself, or even less groundbreaking, as it laid the foundations for quantum theory.
Also, remember that at the time when Einstein's Nobel prize was awarded the general theory of relativity was very new and had only been partially confirmed by experiment (by light bending near the sun and the precession of mercury) so the Nobel prize would have have had to been awarded of the special theory alone.
However, I would not say that Einstein's explanation of the photoelectric effect was not Nobel prize worthy in itself, or even less groundbreaking, as it laid the foundations for quantum theory.
Also, remember that at the time when Einstein's Nobel prize was awarded the general theory of relativity was very new and had only been partially confirmed by experiment (by light bending near the sun and the precession of mercury) so the Nobel prize would have have had to been awarded of the special theory alone.