Exporting the OpenType Layout Feature Definition script *.otlfd from the regular font and importing it into the bold version will transfer the other OpenType features too, besides kerning, but it will only copy the kerning pairs the same as you’re doing now.
If the two styles need different kerning values, then you’re chasing rainbows. Nevertheless, either method will still save a lot of work.
Using Kerning Classes will reduce the work load a little, but not much for your font I suspect.
