These kind of devices are mainly to get hardware that doesn't have a MIDI port (or even USB for connecting an adaptor) - but does have Bluetooth - to communicate with MIDI devices. I haven't seen that these kind of devices can talk to each other without some form of Bluetooth master (like a computer, tablet) in the middle. However, a quick glance and the info wasn't in my native language so I didn't research that much. Under a time crunch right now.

If you want to connect the CVP-96 to the Montage, if it doesn't have to be wireless, you can do it a lot more cheaply with a pair of these:
https://www.thomannmusic.com/the_sssnake_sk366_3_wh_midi.htm
and it won't add any bluetooth latency.

Typical reasons to do it would be to play Montage sounds from the CVP, or CVP sounds from the Montage.

Alternatively, you could also connect one of both of your Yamahas to a computer or iPad, which lets you do other things, but the wiring/attachements needed would be a little different, depending on exactly what devices you're trying to connect. For example, to connect one of your Yamahas to a Mac or iOS device, you can use just a singleone of those CME WIDI Master bluetooth devices, and pair it with the bluetooth in your Mac/iOS device. Yamaha also makes their own version of this, it's the MD-BT01. (I don't know how they compare, though I don't think you can use a pair of Yamahas to directly connect one of your keyboards to the other, as you could with the CME device.) Or for a hard-wired connection that will work with a Mac or a PC, you can use something like Yamaha's UX16.

Rather than ask what the cable/adapter will do, you could approach it from the other side, and post what it is you'd like to accomplish, and then look for recommendations as to what you need to make it happen.

Thank you very much.
Not pretending anything...
Just curious about it...
So I play my CVP and the Montage will sound.
Now I go to the Montage ant the CVP will sound...
Ok.

Yes, that would be a simple and common use for the MIDI connections, whether wireless or hard-wired.

Reasons to connect one (or both) to a computer or iPad are varied... you can use the keyboards to play additional sounds that you can load into your computer/iPad, you can use the DAW/sequencer functions of a computer or iPad to create/edit multi-track compositions consisting of various parts which could themselves be sounds form the Yamahas, sounds loaded ino your computer, or live audio recorded with a microphone (e.g. for vocals)... you can also connect to the computer to use tools to facilitate the editing/management of sounds in your Montage... lots of possibilities!

Thank you...
I think Montage is just more than enough for Fernando...
But I will tell AnotherFernando, just in case...