You Do Need power plug adapter while traveling from Bonaire to Serbia.

Here is Why You Need An Adapter

The outlet and plug type used in Serbia are C and F and in Bonaire are A and C. This is how they look like.

Bonaire

In Bonaire, outlets of type A and C are in use.

Type A

Type C

Serbia

In Serbia, outlets of type C and F are in use.

Type C

Type F