My father side also migrated from Mostar (their family name was Dvizac) about 100 years ago and settled in Izmir. The entire village spoke bosnian. My father used to say that they learned turkish when they went to school, so about 50-60 years they used bosnian. Izmir, I think because of large number of Bosnians living there, is very different than other parts of Turkey.
Cool, Mostar isn't far from where I'm from.
It is my dream to visit Mostar and Bosnia, if life allows. From the pictures I see, it is a beautiful place. I found some Dvizac's on the internet. I was told it is a last name that originated from Herzegovina and of mixed origin, meaning Serbs and Muslims, maybe Croats too, use it. Where are you from and what is your ethnicity?