You Do Need power plug adapter while traveling from Grenada to Bermuda.

Here is Why You Need An Adapter

The outlet and plug type used in Bermuda are A and B and in Grenada is G. This is how they look like.

Grenada

In Grenada, outlets of type G are in use.

Type G

Bermuda

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

Type A

Type B