A very late reply since I have the same problem and can't figure it out.
I have different announcechannels the relevant part of my iobanana.tcl is:
set ioss(announcechannel) "#bla" ;# Default announce channel
set ioss(announce_mp3) "#bla-spam"
## Note: Do NOT define the default channel as an area-specific channel too!
Still it only invites me to the default channel (#bla)...
ps.
Personally I think this is logical because everything in the invite-part of iobanana.tcl points to (announcechannel) and
NOT to the areaspecific announcechannels!
This is probably the same reason why the bot doesn't voice top-10 users in the
#bla-spam channel, AND why it doesn't show the
commandhelp line to users entering the channel... (right?)
Anyone please? -=thanx=-