Your query is close. But you are using the id instead of the timestamp:
SELECT takes.*
FROM takelist takes INNER JOIN
(SELECT max(ts) as max_ts, bucket_id
FROM takelist
WHERE producer_name = 'sean'
GROUP BY bucket_id
) latest_take
ON takes.ts = latest_take.max_ts and takes.bucket_id = latest_take.bucket_id;
An arbitrary takelist_id
is chosen in the original formulation. And it might not be the one you want.