I thought you might find this interesting if not exactly relevant.
I am an army helicopter pilot currently serving in Iraq and there is primarily concrete construction in the area. There are only a few domes that are mostly part of mosques and such but this one in particular is in the middle of an old Iraqi military compound that we now use as a helicopter gunnery range. It is definitely a concrete dome with rebar reinforcement like your own and we had teams shooting rockets at it for months before someone finally was able to punch a hole in it. Even direct hits would often glance off of it, it was pretty impressive.
Not that anyone needs to worry about flying explosives when building their home but i thought it was still a testament to the strength of the dome.
I am just a fan of alternative construction who has been searching your website regularly and I hope to attend one of your workshops when I get home.
Note: This is a copy of an unsolicited email sent to Monolithic on January 30, 2008.