If someone said, "Bosun is amenable." I would think that bosun could be one of two ways:
1. A person who likes to cooperate and get along with everyone in a situation. Someone who has a very agreeable personality and an easy-going disposition. Someone who is very tolerant of others' opinions.
2. A very docile person who is so easy-going, he can be swayed by the will of others. Who is so undemanding, people take advantage of him. Someone who is gullible to the whims of other people.
I think there's a positive/negative side to this trait, and it's possible to have too much of one and not enough of the other.