What is Bosnian black honey?
It is honeydew honey. It is not made from nectar, but from tree parasite secretions. It has a quite different taste from regular flower/nectar honey, and it is much darker. Sometimes it is also called forest honey. 

Wikipedia has a paragraph on it: http://en.wikipedia.org/wiki/Honey#Honeydew_honey

There is a slim possibility that it is not a real honey at all, but pine honey, which is actually a jelly made from pine flowers/leaves (it uses the fresh tips where the needles are very soft). It is used as a bee honey substitute, not a fruit jelly substitute, and the name also includes the word "honey", so there is a chance for miscommunication, especially if a language barrier is present. But I think you'd have described the taste differently. It is also a richer taste than normal honey, but a bit sharper, not caramel-like mellow, and the pine resin aroma is discernible.