Are you adding fresh yeast or just letting the bugs finish it? The reason I ask is bugs don't produce the same levels of co2 as sac.

The Beer will be 6 months old and yes my basement will be about 68 degrees in July. I am planning to use Palmer's nomagraph to find the sugar amount for 3 volumes of Co. Also now I am planing to us about a 1/3 of a pack of O 4 Yeast in the bottling bucket. I am thinking that I will pick up some champagne bottles just in case the Co creeps up.

Bottle conditioning sours or wild beers can be the most challenging. One thing you should do is check the final gravity before you decide how much sugar to add. If its below 1010 then most of the fermentables are gone and prime accordingly. Remember that if the bottles are left warm the brett will slowly chew on the remaining and the co2 will creep on you. If you have a high FG still lets say 1014 then you really have to be careful. You could prime accordingly but must keep the bottles cold after initial priming, since there is just too much sugar left for the bugs to work on. You could add half the priming sugar and let the bottles sit warm until the bugs have chewed through enough of the remainder to reach desired co2. Or you can let the beer sit in the carboy until the fg is below 1010.