Danny,
You are correct, BB's iPad and iPhone apps require the desktop version of Band-in-a-Box.

They are:

1. Band-in-a-Box iPhone. This loads and plays songs by connecting to your desktop version of Band-in-a-Box. Files transfer as BB songs and mp4 (m4a) files for the audio. Once you transfer them, you can play them on the iPhone version without being connected, but to regenerate them or get new ones, you need to reconnect to BB Desktop (which you can do over a local LAN or over the internet WAN.
Typical use here would be to prepare your favorite 100 BB tunes, with melodies and RealTracks set up how you like them. Then transfer the 100 tunes to your Iphone BB, and you'll always have those files ready to play on your Iphone, showing you the chords, while you hear the full RealTracks arrangement, including melodies, and whatever synths, VST effects etc you have in BB Desktop.

2. BB Remote. This is a remote control for your desktop version of BBW 2011.5 or higher. Sounds come from your desktop version, and the iPad just functions like a wireless remote control, to load and play songs (you get a display of chords on the iPad and highlight bars as the song plays.

Note that the above is written about the iPhone, but also applies to iPad (the programs work on iPad in iPhone 2X mode), and also there are Android versions of both programs.

Have Fun!
Peter Gannon
PG Music Inc.