I meant that when I tested it, I called up Otto and renegotiated my peace: peace + alliance against Maya + ROP. So perhaps the ROP rep is damaged by association with the alliance, which I was definitely responsible for breaking.
I could have done it in two steps: (1) renegotiate peace: peace + alliance, (2) ROP for ROP, no strings attached.
Re: Portugal or Maya. I prefer the Mayan war simply because they should have fewer units - they were at war with India, and Portugal was not. This whole theory about the Portugese blocking the choke seems a bit fantastical to me, but they should still be in the area helping out.
My prediction for war with Maya would go: we wait a turn or two to heal our units. The Mayans in India start walking home. We dow the Mayans and buy in Portugal and the Inca, and use our units in India to kill the stray Mayan javelins - there's only six units isn't there? Taxpayer will have to say if he saw more somewhere. We don't need to worry about axes and spears, as they can't take our towns if we have defenders. Let the Portuguese kill them. We heal up a bit again, if necessary, then load up into the dromons (maybe we set up a ship chain beforehand) and sail around to the Mayan towns. By now, fresh Mayan troops and our Portugese allies should be fighting in the grass area between India and the choke - of course we need a small contingent to stay in India for safety's sake, perhaps it is the AC army, which would otherwise have to fight its way over the choke. We take out the probably lightly defended Mayan towns.
Of course the trouble with this whole plan is that we are pretty short on units right now. But that is also a problem if we go to war with Portugal. Maybe we will find that we have to go a little slower for a while.
Oh, also the Mayan land may be a bit dry right now, but at least it is closer to Byzantium than Portugal. Chichen is at RCP11, whereas Lisbon is at RCP20.