今、ようやくツケがまわってきたのだろう。

、。

Now the tab is finally coming due.

Literal

Now, finally tab [subject-が] came-around-[continuous-てきた][explanatory-のだろう].

A reflective regret. ツケがまわる ('the tab comes around') is a set idiom from the practice of drinking on credit at bars — your tab (ツケ) eventually has to be paid. Figuratively means 'past actions catching up with you, the bill coming due for your sins.' ~のだろう is the reflective suppositional. ようやく ('finally, at last').