Which way will pears last longer in a bowl or keep them apart.
If you are keeping them at room temp they will continue to ripen until overripe, whether in a bowl or apart. I don't think a bowl makes too much difference unless the bowl were covered, then they would ripen a little faster. They will ripen less quickly if kept in the fridge.
Keep them in a bowl until they are perfectly ripened then move to fridge to hold them a little longer
I have found keeping them apart (like on a platter) reduces bruising when they ripen.
Eat them sooner rather than later. Perhaps not the advice you wanted, but pears can get really mealy and mushy pretty fast. If you absolutely must keep them longer than is ideal, put them in the fridge.