you cannot extrapolate the VSEPRT to other molecules such as PH3 simply because the greater size of the phosphorus atom basically affects the inter electron pair repulsion.
It's all very well to say that NH3 is 107º therefore PH3 will be as also - it just isn't.. there are other factors to consider such as the polarised nature of the N-H bond when compared to the P-H bond. The H-P-H bond angle is 93.7º even though it is pyramidal
This also applies to H2S and H2O - they do not have the same bond angle.
The VSEPRT does not predict bond angles , rather it explains them based on some rather simplistic and easily understood "rules"
Just learn the simple molecules H2O, NH3, CH4, XeF4, etc but do not be at all surprised by seemingly similar molecules with very different bond angles.