Hi Chon,
As I know, if this is related to the Opportunity then you can rollup to its Potential Customer (Account/Contact) Related Associated Activities, but not the other way.
So, you can only rollup to the related child activities, not the parent.
In this term, Contact is the parent of the Opportunity, so that you can see all of activities from the Opportunities through Contact Associated View rollup activities right, but you cannot make it 'vice versa'.
It wont appear in the Opportunity.
You have activities: Call A, Call B, Email C, Task D, SMS E, and so on with regarding field to: Chon (A Contact)
Then Chon have Opportunity: Interested in iPhone 64GB for instance, then you have activities set to regarding to this iPhone opportunity.
In the Chon screen, you can see the Activities from the iPhone record (opportunity), but from iPhone Opportunity, you wont be able to see Call A, Call B, email C and so on, because Chon is the parent of the Opportunity.
But, you can see the Quote activities in the iPhone record

Because Quote is the child of the Contact.
That is the rollup design,.
Okay, if you want to have the Activities appearing in the Quote, you can either manipulate its UI through report or web resource or associated view of the Account..
Or you can try to create the Activity (copy Activity to Opportunity activities), but you might have flag to indicate that this is actually Contact's activities not Opportunity activities, because you are going to have activities regarding field to its Opportunity itself, not Contact.
Hope this helps you.
Thanks.