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

Here is Why You Need An Adapter

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

Palau

In Palau, outlets of type A and B are in use.

Type A

Type B

Bonaire

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

Type A

Type C