Association:

(often in names) a group of people organized for a joint purpose.
"the National Association of Broadcasters"
synonyms: alliance, consortium, coalition, union, league, guild, syndicate, federation, confederation, confederacy, conglomerate, cooperative, partnership, affiliation, organization

Club:

an association or organization dedicated to a particular interest or activity.
"a photography club"
synonyms: society, association, organization, institution, group, circle, band, body, ring, crew

In my mind, Association brings to mind a business, a political group or a not-for-profit with altruistic goals or for some particular agenda. It does not bring to mind a hobby, or anything engaged in for fun. It also appears that a club is a specific kind of association. Do we want the more general or specific term? I also wonder how significant the name of the group could be in trying to secure a grant.

I am not against the word "Association," but I prefer "Club." It seems to describe exactly what we are, whereas the word Association is simply a gathering of people and gives less of an indication of what we are.

Michael Siskin