No, the configuration you described will only listen to one side of the conversation.
In order to listen to both sides, you need to configure it in Scanning Mode. Please refer to the application note AN14 Continuous Scanning Mode for Asynchronous Topologies for more details on this mode.
http://www.thisisant.com/pages/developer-zone/ant-application-notes
Keep in mind that you will need to configure it as Rx-only, otherwise, the "sniffing" device will interfere with the communication by acknowledging burst/ack packets.
Also, please be aware that we highly recommend looking at debug logs of the serial ANT/MCU communication of both sides of the link, instead of trying to use a third device as a sniffer, when trying to debug ANT-FS issues, for several reasons:
* interpreting the sniffed messages is not as straightforward, since all messages share the same channel ID, and the Rx-only scan mode cannot differentiate between broadcast, ack and burst packets.
* since this is a wireless system, what you see on the scanning node is not necessarily what you see on the two endpoints (i.e., seeing a packet from the master device in the scan node, does not necessarily mean it is seen by the slave, due to variability on the RF environment).
Developing against the PC client/host helps a lot as well. Validating each side of the link against the PC tools tends to provide much more useful information, and is a less tedious process.