Bump story and a question:

Girlfriend & I travelling on Delta JFK-LAX 3 weekends ago, flight is overbooked, I offer our seats when attendent B calls for volunteers (though slightly pissed, as checked in with attendent A, and had her start a volunteer list with our names on it).
Next flight was a over 6hrs later, but each of us got:

- $400 Delta travel voucher (choice of that or $250 cash)
- $10 lunch voucher
- upgrade to Delta Business Elite

BE allowed us to spend the time in the Crown Room lounge (MUCH nicer than in the terminal). Plus, because we got the business class transcontinental mileage bonus (10k miles) for that segment instead of the coach one (6k miles).
This was all on a $209 pp websaver fare. Totally weekend cost was $846 (departed Sat afternoon, return Wed morning), but received $800 in travel vouchers, and almost 44,000 FF miles.

Question - we could got have gotten bumped from the next flight (following flight would have only an additional 2 1/2 hr wait) but my girlfriend didn't want to lose our BE seats.
If you have First/Business class seats (whether purchased or upgraded), and you give them up to be bumped, are you likely to get F/B class on the rebooked flight? If I gave up my first rebooked BE seat for a 2nd rebooked coach one (maybe no room in BE), could I expect/ask for any extra compensation? How about a systemwide upgrade voucher to use on a subsequent flight?
I would certainly ask for a pass to the First/Business lounge. If they want me to wait for a later flight (especially 6+ hrs), they can let me do it in comfort.

Jeff