It depends on your training goals.
If your only training is cardio then it's fine to mix it up and do some glycolytic work (heart rate above 150bpm)
If you are doing HIIT or interval training as well then it's not much point going over 150bpm with the cardio unless you are in final stage of stage peaking before a race or some high intensity event.
If you are also weight training or just supplementing HIIT sessions just keep it at a moderate rate to get all the benefits that come from anti glycolytic training. HIIT is almost fully glycolytic training so you don't need any more of that in your cardio sessions.
It doesn't hurt to go above 150bpm temporarily a few times just keep most of it in the anti glycolytic zone.