Here is another strategy for using points rather than cashing them in for OBC. Assuming you are going to cruise on Celebrity again, use the points for a reduction in the cruise fare. I always do this right after I have done a final payment. The reduction in cruise fare then shows up as a credit on my next Celebrity BOA statement.
On the cruise, I then use that credit card to pay for any onboard expenses, thus accruing more points at the bonus level.