Cut one massive blighter down, shredded it, and mixed it with a load of other shreddings composting down, only to then be told by a neighbour that the Yew is poisonous!
Have I ruined the compost that I was making for my veggie patch?
It is poisonous if eaten but was also regarded as a spirtual tree with healing powers ???
You'll need to wait for an expert to come along, but I don't think that the toxins would persist through the composting process.
It rather depends on just how much compost you intend to eat.
The poison is Taxine, an alkaloid. No doubt it would break down during composting, but someone out there may know more than I do.