Q.What is the preferred ratio of bone meal to compost
What is the preferred ratio of bone meal to compost when making bulb fertilizer? Are the components measured by volume or by weight?
Here is another link about proper planting and care of daffodil bulbs.
Bone meal is not a recommended fertilizer for daffodil bulbs, containing to much nitrogen. You could use it as a top dress after the blooms have faded to feed the bulb for next spring.
http://www.bostongardens.com/time-to-plant-tulips-and-daffodils/
Since I wan't sure what bulbs you were referring too, I listed a few links for you.
I myself urge less is more when adding bone meal to my bulb beds. To much tends to overfeed the bulbs and I get more greens then flowers.
https://www.gardeningknowhow.com/ornamental/bulbs/daffodil/fertilizing-daffodil-plants.htm