I have exactly this setup and it works fine. To connect an additional AppleTV, I have an audio TOSLink switchbox (Lindy 4 Way TosLink Digital Optical Audio Switcher 70416) in between, which can also be controlled via Harmony. HDMI from SwisscomTV and AppleTV go directly into my Philips TV. Audio goes via Lindy Switchbox into the Playbar. Alternatively, if your TV has a TOSLink output, you can connect the TV to the Playbar. The sound then goes via HDMI to the TV and then to the PB.
I'm not entirely happy with the Harmony myself, but that's another topic....