Brake bleeding over 2 days

[thinkingvolvo]

Hi folks - I started the brake job on my XC90 thinking I will finish off in a day. Did the rear brakes and bleed the rear wheels, then jacked up the front and started the front, only to realize that I needed new Caliper bolts and pins. The parts were not available at local dealer, so car will stay ramped up in the garage... Now that I have already bleed the rear, it is necessary to bleed it again or is the system for each wheel completely isolated? i.e. what are the chances of air bubbles entering the rear system since its just sitting there? BTW, i am using the motive power bleeder. Thanks in advance...