Thanks so much for all of the detailed information and advice. This is the first time I have used gastight teflon around the bleeders and I think it did improve the prevention of air being sucked back into the bleeder. I would do it again like this. I would also go the extra yard to manipulate the front calipers to extract the last of the air.
I have re-inspected the Goodrich braided lines and steel fittings and they are very very solid. No issue there re metallic differences.
Dougs comments on gas porosity in metals and hoses are very interesting . At the risk of going off topic I offer a personal observation on this.
A good example of gas porosity is in heavy wall high pressure pressure vessels working in hydrogen rich environments. These in operation can develop blisters on the inside surface where hydrogen seeps through the steel ( one molecule at a time ) and binds up at a point of laminar inclusion in the plate. This results in a high pressure hydrogen bubble inside the steel that, if untreated, will split the pressure wall. Treatment was simple and nerve wracking - use a mag drill to puncture the blister.
Unfortunately the high pressure hydrogen would come out the hole when it reached the blister and spontaneously ignite - very tough on the front of the mag drill and on the operators nerves !! ( .....you always seemed to be holding your breath ....!!)
This was the most graphic example of osmosis of gas through metal that I have seen. A little off topic for this post but interesting none the less.