Just an update on this problem: I contacted the "Eternabond" people and they were kind enough to get back with me. They wanted details as to how I cleaned this site before applying the Eternabon tape and photos of the affected site. I sent them to their rep and he responded with a phone call (not many company's do that anymore). Tom stated that this was a multi-problem situation with the following factors:
1) There had been moisture/water intrusion underneath the EPDM membrane just a week prior to my repair job and there "probably" was moisture still underneath the membrane. After I did the clean up at the antennae base, remounted the base, applied the Eternabond tape and the lap sealant I may have (I'd now say most likely did) create a "steam chamber" underneath the EPDM roofing material in that one area. Creating a steam underneath the membrane would make the EPDM get hot and bubble up.
2) Using "Simpe Green" was not the best thing I could have done., although recommended by the local RV shop. Simple Green contains certain chemicals that do not "flash off" readily. This residue may have attributed to the Eternabond tape not adhering as it should have. Tom recommended Acetone (which the RV place told me not to use as it is a petrol product) or de-natured alcohol to clean the EPDM material before applying anything.
3) Tom also mentioned that he thought the Winegarrd antennae bases, as I have, used a rubber type gasket to seal between the bottom of the antennae base and the roof. By using this type rubber gasket one would only have to mount the base, snug the screws down enough to hold the base, then use lap sealant only around the outer edge of the base. I actually did find a parts diagram on Winegarrd's website that showed a rubber gasket for the base, but-one would have to buy the base kit to get the gasket. I certainly like the idea of a gasket then the lap sealant around the edge only.
Being as we are to have beautiful weather for the next 4-5 days I am in the process of removing all that I messed up and starting over.