For those of you who might not know where Tonga is:

I just looked it up on Google maps and found that it is to the east of Australia, New Caledonia, and Fiji.

Then to the east of Tonga is Tahiti. I asked online if this eruption was affecting air travel but looking at this area it is more likely that jets would just take a wide berth of the area and be okay because it is so very remote there likely from regular air routes for larger jets. So, jets will have to think about wind directions if in proximity of Tonga.