There are also the possibilities of a Spanish Dominica and/ or a Spanish St. Vincent and the Grenadines, but Dominica and St. Vincent and the Grenadines would be more difficult for the Spanish to colonize than Grenada and the actual Spanish Caribbean island colonies such as Cuba, Puerto Rico, Trinidad and the Dominican Republic. In any event, any Spanish Dominica and/ or Spanish St. Vincent and the Grenadines would share the same fate to them as the Spanish Grenada's fate mentioned above to any Spanish Grenada.
Ditto with any other Spanish colony among Caribbean island colonies and nations such as St. Martin, St. Barthelemy, St. Lucia, St. Kitts and Nevis, the Virgin Islands, Barbados, Anguilla, Montserrat, the Antilles, Antigua and Barbuda and the like.
Having said that, the Spanish, if they took every Caribbean island they discovered by exploration from 1492-1503 and maintained the same South, Central and mainland North American empire they had otl, would be holding all the Caribbean islands excluding the Cayman Islands, Sint Maarten/ Saint Martin and some of the Virgin Islands. Assuming that despite the increased Spanish Caribbean empire, the Spanish could defend all those Caribbean empire's islands from foreigners while ensuring the general course of history proceeded as in otl (a bit unlikely since most to all the profits from sugar, slavery and colonialism from some of the Caribbean islands in question would be going to Spain rather than to its English/ British, French and Dutch enemies), the Spanish empire in the Caribbean would last that way while Britain/ England would add as many of the Virgin Islands to its colonial portfolio to replace Jamaica with non-British in otl Virgin Islands. In the Seven Years' War, the British would use the resources used against French and Spanish Caribbean Islands to go for and capture French Louisiana (later exchanged for Minorca) instead while Spain would stay neutral with increased confidence in defending its bigger than otl colonial empire alone. During the American Revolutionary War, the Spanish would capture Louisiana and Minorca instead of Florida and Minorca and the reduced finances from Britain might butterfly the Nootka and Falklands Crises in Spain's favour (or Spain might exchange Minorca or French usage rights in Dunkirk for the Falklands and Gibraltar or French Senegal or an alternate French Cayman Islands for the Pacific Northwest/ Nootka), followed by a Caribbean and Americas-wide version of the post above. The Haitian Revolution would proceed as in otl, but against Spain in addition to France, and Saint Martin might be exploited more for slavery to the extent of the Haitian Revolution being repeated successfully in Sint Maarten/ Saint Martin.
During the French Revolutionary Wars, the Spanish would lose Trinidad and Gibraltar in this scenario rather than Trinidad only as in otl. The Savoyards would lose their homeland (if butterflies allowed Spain to take Parma, Naples, Sardinia and Sicily for Spain in the Wars of the Quadruple Alliance, maybe Minorca and Gibraltar in the latter war) and their existence with associated butterflies after the Napoleonic Wars, which would see France's defeat and loss of Mauritius and the Seychelles. Spain would lose Louisiana, Nootka Sound and Florida to the US and its Latin American mainland colonies around the same time, followed by a Caribbean and Americas-wide version of the post above other than the Falklands.
Italy would likely be unified under the Bourbons (likely the Spanish Bourbons) with resulting butterflies to Italy and Spain. For example, a Spanish or a Spanish-aligned Bourbon unifying and ruling Italy might send Spanish troops to conquer Ethiopia for Italy successfully in 1896, with butterflying of the 2nd Italo-Ethiopian War, the Anschluss, WW2 and resulting butterflies. However, a non-Spanish, non-Spanish-aligned Bourbon Italy might bring a general course of history as in otl, but with Spanish and Argentine control of the Falklands in the 19th and 20th centuries respectively.
Finally, the Cayman Islands could be added to Spain's colonial portfolio in 1503 and exchanged to Britain in 1783 for a Spanish Gibraltar.