If you control more than one Starlight Spectacular, each one calculates its bonuses separately. For example, if you control three creatures and two Starlight Spectaculars, each Spectacular will give one creature +0/+0, another +1/+1 and the third +2/+2. You could choose a different order for each one though.

You don’t have to line up the creatures in a parade line to get the bonuses, but it would be spectacular if you did.