Most of native Romance speakers of Bosnia were pushed to Dalmatian coast and some islands by Avars in early middle age. They were speakers of Dalmatian language
https://en.wikipedia.org/wiki/Dalmatian_language
In the late middle age some Vlach groups from east arrived to Bosnia as sheperds (Istro-Romanians and probably some Aromanians).
There is mountain Cincar in Bosnia near Livno. Cincar means Aromanian
https://en.wikipedia.org/wiki/Cincar
After destruction of Moscopole by Albanians and Turks in 18th century some Aromanians came to Bosnia. They were not numerous, only 2-3 villages.