According to the instructions (page 6), they'd be bi-wired not bi-amped. (Also note the impedance switch setting required. Table for correct setting on page 4.)
Occasionally 'stereo' amplifiers are switchable to offer full bi-amping, rare but over the years they have existed.
Interestingly the Marantz MC-R 500 and 600 series do offer these facilities, the power amplifier section can be switched to provide 4 separate channels to give true bi-amping.
Whether this is a worthwhile feature or not is another matter.
The option to switch to A+B is noted in the manual.
You can use the two outputs to drive 1 set of speakers but by the term Bi-WIRE.
For this you need speakers with 2 sets of binding posts and a removable plate. I.e. Wharfedale 10.1.
When the plate is removed the cross over circuit between the tweeter and woofer is removed and the amp drives each unit seperate.
Some swear by it some don't.
You can also biwire by just adding 2 sets of cable to the same amp posts and using just A or B or as mentioned use 2 sets of speakers for the same output, fo example one set of speaker in the dining room and another set in the lounge etc.