I own a 300/2 JL Amp and I am about to buy the MB Quart premiums. The premiums are rated for 60-130 watts. The 300/2 pushes a true 150 X 2 will they blow.
should be fine you won't actually drive the amplifier to 150 watts RMS anyway.. that's at peak output. you'll only use a fraction of that power continuously during normal use.
i own those speakers. you wanna give them around 100 rms so tune down the amp. i have 4 going on a 300/4 and they sound great on 75 rms but before i got the rears i had to tune the amp way down.