Now, from this group, and people I talked to about this situation, it
appears the bonding agent was not necessary, although I would have
liked it or, as one person said here, at least a power wash. As for
as a final coat, people in this group say I can have a third coat
applied to what is there now (the suposed last coat). Do you all feel
this is so? I have read that the brown coat is quite smooth with
little or no scoring or keying. Yet is ready for the final finish
coat.

the finish coat is just that, which is purely decorative to give you
the desired look and feel. The paper/scratch and brown is doing all
the work!... If you are after a rough knock down type finish, you
should be fine to go ahead an apply it directly to the brown... A
really smooth finish coat will be alot harder becuase you would have
had to do it when the brown coat was still a little green (wet).
Sounds like you desire a rough finish coat anyways, so have them toss
it up!... I wouldn't sweat all the issues of bonding agents etc, its
just roughly 1/4 inch of concrete bonding to another 1/4 inch, there
is very little load so to speak? Stucco cracks/stucco fails, stucco
is easily repaired from normal issue as is ages...

Unfortuneately, I have done alot more stucco than I care to admit!