Yes. A1000 and Gary based Amigas can access both CIAs simultaneously (if both select bits are active). I don't know if it was designed to do that or if it is was only a side-effect.
Gayle and Fat Gary only allows single CIA select, only bfexxx or bfdxxx space activates CIA select line.
More detailed here:
http://eab.abime.net/showpost.php?p=...&postcount=210