The term Friend of the Coven doesn't just refer to someone who is friendly with some or even all of the members of Renewal coven but rather to individuals who are specifically and formally friends to the Coven itself.
A Friend of the Coven is someone from a different tradition who sometimes joins the Coven for Sabbats and on occasion Esbat rituals. A Friend of the Coven is always the equivalent of a first degree or higher within their tradition (an adult member able to represent that tradition earnestly).
Becoming a Friend of the Coven is a fairly long process and involves getting to know and getting to be known by the Elder's of the Coven and is confirmed through a formal ritual of friendship.