I dont know if this applies to the new bonus, but I came on in early 2016 when the sign on bonus was only 5k. We only got a chunk after IOE and the remainder at month 10. I dont know if that applies still, but I could see them structuring the bonus in the same fashion if its 15k.

Thats for the people asking about having to repay the bonus if they leave. In our case, we just got what we got, depending on how long we stuck around.