I have taken a more systematic approach this year.
1. I am actively reducing the yellow jacket population with baits/traps. This started in March.
2. I am using insect netting this year to attempt to exclude these pests as well as make the bird's lives harder.
3. I built an extension on the trellis consisting of "T" shaped pieces that suspend two wires above the vines. I will drape the netting over this apparatus to keep the nets way up above the fruit zone. No pecking through the netting. In addition, this can be used like a quasi VSP trellis, to allow some of the shoots that want to up upward to do just that.
As you can see from this shot of the fruit on some of the more mature vines (these are in their 4th leaf) I have a good crop to protect this year! Crossing fingers I might actually make some wine from my own grapes this year.
There is a small section of the 5th year vines that are already starting veraison (changing color) so I am now in good shape to get the netting on this week when I can drum up another set of hands to help.