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

Here is Why You Need An Adapter

The outlet and plug type used in Slovenia 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

Slovenia

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

Type C

Type F