Hi Devs
Hope this helps you:
1. I was hired in the marketplace to harvest crops and flowers which I did and successfully claimed the bonus.
2. I watered the employer's farm with the brown sprinkler and the flowers were instantly ready to be harvested.
3. I harvested the flowers again and again I successfully claimed the bonus.
While I don't know if the flower harvest is double or not (I don't know how many flowers I had in storage to start with) this is a beneficial glitch. Its always difficult to get enough flowers to fill the flower facility to 100% each time.