WARNING!!!
There are BIG differences between what you can do with vacation on a hard line vs. a reserve line. You asked about bidding vacation with a RESERVE line and people are giving you techniques that would only work with a hard line, so be careful!
For example, reserve line holders may not EXPAND their vacation, they may only EXTEND their vacation by the days calculated in that formula. If you have 7 days of vacation and you bid a RESERVE line, then you have a choice between 7 and 10 days of vacation. If you elect to EXTEND it to the maximum 10 days, then your bank will be docked 10 x 4:36 or about 46 hours. That is it! Since there are 15 R days in NOV, you would owe 5 R days. If you want to knock out more hours than that, you will need to bid a hard line, and then you would be able to use some of the techniques described above.
Try the search feature, this has been asked and answered many times before.