That's an excellent idea if you want to use your miles to go to the South Pacific region. The earlier and/or greater bonus would put you over 60K with no need for an additional trip (and probably less expensively than any sufficiently long trip). If you don't think you'll want to go there, since you're already in business class I don't think the added benefits of earlier/higher status are worth the cost of a Challenge.

(Of course, if you pick a different program, this AA-specific option is irrelevant.)