Details...
1.-For any kind of drop (adena, quest, items in general that use any slot of your inventory) you have to be in near range with party
2.-Exlated quest items are... well... items so read point 1.-
3.- EXP
a) One thing is EXP given by killing mobs
b) Party bonus EXP is a diferent thing
Let's say a mob gives 100 EXP if you kill such mob alone
If you are in a party when killing the mob, and the other members of the party are near range, the mob will give 100 + a party bonus exp (for example +20) = 120 EXP divided by equal between all party members NEAR RANGE, so if your party is made by you and 1 more ppl, those 120 are divided by 2, so 60 each one
BUT
If the other person is not in range (is in the city for example), then you, the killer of the poor mob, will gain the 100 (mob exp) + 20 (party bonus exp) = 120 EXP only for you, as the person left in the city will gain 0 (zero) EXP
AND
If you are murdering that poor mob in one place, and at the same time you are in party with other person who is killing another different mob in a galaxy far far away... just for being in party and faaaaaaaaaar away, you will get the 100 EXP of your mob + 20 bonus exp for being in party, and your party member will get 100 EXP of his/her mob + 20 for being in party, in these case both of you will get 120 EXP for killing poor mobs in separate locations...
SO
You gain 100 EXP for killing a mob in solo , 60 EXP for killing in party with people in range and 120 for killing in party out of range (this is the so called distant party)
Regards