According to IATA, the Multilateral Interline Traffic Agreements (MITA) is:
an agreement whereby passengers and cargo use a standard traffic
document (i.e. passenger ticket or air waybill) to travel on various
modes of transport involved in a routing in order to reach a final
One Multilateral Agreement concluded with another airline through IATA
results in joining a partnership of the growing network of over 350
participating worldwide domestic and international airlines.
My reading of that, is that there is only one MITA, and each airline/transport body signs up to the IATA MITA and becomes bound by the agreements found within the MITA manual.
Unfortunately I haven't been able to find a free resource with a current list of members, however this bankruptcy document from 2011 appears to provide a list of member airlines at that time. Airlines such as KLM, Qantas, British Airways were at that time signatories of MITA.
A couple of posts on Flyertalk discuss the airpass bought in conjunction with Hahn Air and BA with which Gol doesn't have bilateral interlining, hence the reference to the IATA MITA seems applicable.