OK, so you did not actually use two LEDs which drops voltage by 2.5V. With two LEDs, the total voltage on the resistor and transistor is Vce+Vr = 4.5 - 2.5 = 2.0V (according to OP's claim)
I just downloaded datasheet for PN2222A and your 200mV Vce at 100ma Ic seems reasonable. The 1.0V Vce claimed by OP is too high and according to chart, it could only happen at 500mA. At 150mA, Vcesat should be around 0.3V according to datasheet.