Trinidad and Tobago is a fascinating country.
A POD in the Seven Years War would mean that the islands would remain in Spanish hands. That means that they'd most likely become part of Gran Colombia, and then Venezuela. Without British rule, Trinidad and Tobago's unique Indian-Caribbean culture would never develop. The country would look a lot like Nicaragua.
Trinidad didn't actually go to Britain until 1797 (ownership confirmed by Treaty of Amiens in 1802). Tobago had been under British sovereignty before, but by the late 18th century was in French hands, and didn't actually revert to British rule until... 1814?!
Trusting the Armenian Genocide's word on it, the British didn't pay much attention to Tobago through the 19th century either, resulting on its unification with Trinidad in 1888/9 (this is a small POD in itself: had it not happened, we would have separate independent states in Trinidad and Tobago, two olimpic teams and... that's about it).
But assuming the British seize neither of them, Tobago would stay French, and being essentially another Martinique. Meanwhile, and given the independentist poor record on maritime invasions, Trinidad might stay Spanish. A big part of the white population was actually French, and could very well choose to stay with Spain if they don't feel connected with Venezuela/Gran Colombia and/or hear of what happened in Haiti and feel that a local revolution would trigger a slave uprising and genocide of the white population, mirroring OTL Cuba.
Now the questions become how long does it stay Spanish in the 19th century, and what kind of butterflies does it cause. Assuming the road up to 1898 stays the same, does the USA decide to go for it, or does not and this causes it to not go for Puerto Rico post-war either and stick to Cuba only?
Also, why did you mention Nicaragua? Geography and oil (discovered in the 1850s) would mean a closer similarity to Venezuela, obviously if it does go to Venezuela upon independence, but also if it somehow turned into an independent republic of its own.