Bolton is contracted for 5 more years or something, he's not going anywhere under any circumstances.
DGB is an interesting one. He had amazing aerial skills when drafted but hasn't come on as expected through the Hawks. He can still take marks but the rest of his game hasn't improved as hoped. Injuries have also hampered him. I wouldn't really go paying for DGB at the trade table but he'd get a spot on the list to see how he goes.
He turns 22 and is out of contract at the end of the year. If he can't get in the struggling Hawks side, he should probably look for better opportunities.