provided by Star2Billing S.L.

Yes it will still bill because the signaling path should still include Asterisk; it's just the RTP streams that flow directly between endpoints.
This means you cannot do anything that involves manipulating the media streams. One obvious side effect noticeable by the users is that when a call is due to be terminated due to lack of credit they will not receive any of the audible warnings at 60 (61?) seconds and 30 (31?) seconds. In the context of a machine used for wholesale billing this is not necessarily a problem. I think the ability to press * for follow-on-call may be lost too.

This ticket and this thread may also be of interest to you.