You Do Need power plug adapter while traveling from Guinea-Bissau to Bonaire.

Here is Why You Need An Adapter

The outlet and plug type used in Bonaire are A and C and in Guinea-Bissau is C. This is how they look like.

Guinea-Bissau

In Guinea-Bissau, outlets of type C are in use.

Type C

Bonaire

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

Type A

Type C