socrates,
depends on which war you're talking.
1762: I don't think the world will allow Spain to keep Portugal, so you're likely to see some nibbling at the edges of Portugal, probably taking some brazilian territory (especially colonia del sacramento, but possibly portions of Rio Grande do Sul). Mostly, they'll be trading giving up Portugal in return for all the spanish territories captured by Britain, and trying to squeeze Gibraltar out of the deal.
After Spain throws it lot in with Napoleon, it'll try to keep as much as possible. OTL War of Oranges, Spain was supposed to take and keep the northern provinces. Spain stopped after humbling Portugal and only kept a small region around Olivenza. OTL 1807, they were supposed to absorb all of Portugal and give Godoy a kingdom in the Algarves. In both of these wars, France had the upper hand over the rest of the world, so Spain probably could have gotten away with it as long as Nap remained on top. the presumption is that Nap doesn't try to take over Spain, so he doesn't get mired down there, and maybe he stays on top longer.
At that point, presuming the royal family is captured, Britain is going to make a play for Brazil, locking up the ports and establishing a protectorate. Angola and Brazil go together like peanut butter and jelly (angola was basically a colony of Brazil, which in turn was a colony of Portugal), so Britain probably doesn't separate them. control of the sea between them is a good way to keep the Brazilians in line. Britain probably takes over Mozambique. they don't really want it, but they want to block the Boer republics from having a port.
If the royal family escapes to Brazil, you see OTL. Presuming Nap stays on top long enough to have the Portugal merge with Spain become permanent, I see a much stronger Brazil than OTL. Although the war years saw Brazil improved immensely, the growth spurt halted abruptly with the court's return to Lisbon, and then reversed during the Pedro I rule and the regency period after Pedro gave up and returned to Portugal. Keep them, and the treasury, in Rio, you're going to see continued growth. You're going to see a stronger Brazilian empire (the former Portuguese empire, minus Portugal) than we saw the OTL Portuguese empire, minus Brazil. Therefore, Britain may not be in a position to kick the empire around as they did OTL. they could do it, but it would be a lot harder than it was OTL, which defeats the AHC.