You won't earn any miles on a Montenegro Airlines operated flight even if it is AF coded. In order to earn miles, it is not sufficient to simply be Skyteam marketed. The flights must also be operated by a Skyteam member airline. Montenegro Airlines is not a Skyteam member. Even when operated by a Skyteam member, there can be some exclusions (for example, Jet Airways flights earn no miles when AF/KL coded). Always read the full T&C's.

"Unless otherwise noted, mileage credit is only applicable to SkyTeam-marketed flights operated by a SkyTeam member airline. Mileage credit is not applicable to a SkyTeam-marketed flight operated by another airline."