Just received an email (4 hours ago) saying
Your bounty on the question … iPhone: How to ensure iBook files are stored locally … ended and will be auto-closed after the 24-hour grace period expires. Please review the answers. If you feel one of them deserves your bounty, award it by clicking the bounty icon to the left of the answer.
It's not 24 hours yet... but I cannot see the bounty-reward icon.
I must miss something... please let me know what!
-- edit --
Cannot see the alarm clock ... please see the screenshot below