You suspect a link between the grubs and the tomatoes, but it's more likely that the grubs are ubiquitous and in horde numbers. They're part of the whole shebang. Tomatoes won't be hurt by them if they're June Bugs; hard to see from that pic's angle..

another angle. appreciate the quick feedback.

Agree that grubs in the soil are a normal part of any garden. We all have them. It is the rear end of the grub, the raster, that determines what type it is and detailed close up is required. You can make that determination at the link below. They are no threat to your tomato plants.

Types of grubs by raster

Do they eat any plants?