I don't know about them, but the Spanish ambassador to Paris (the Count of Aranda) did expect the US to become a superpower, "an irressistible colossus" in his words in a report dated 1783 to the King of Spain. He even made plans to stop that, but his plans fell on deaf ears. I'll translate his opinion on the matter, leaving the plans aside as they are not relevant to the question:

I mistrust that the new power formed in a land where there is none to contain its projects will incommodate us when it shall be in condition to do so. This federative republic is born, so to speak, pygmy, for it has been given shape by two powers, Spain and France, helping with their forces to make it independent. Tomorrow it will be enormous, as far as it consolidates its constitution, and later shall it be an irressistible colossus in those regions. In that state, it will forget the benefits it has received from both powers and shall think only about its own enlargement. The freedom of religion, the ease to settle people on immense lands, and the advantages offered by that new form of government shall call in peasants and craftsmen from all nations, for the man goes where he thinks he shall make fortune, and within few years shall we see, and deeply lament, the rise of the colossus I mentioned before. Enlarged that Anglo-American power, we shall think that its first goal shall be the entire possession of the Floridas in order to dominate the Mexican Gulf. Taken that step, shall it not only interrupt our commerce whenever it wants, but it shall aspire to conquer that vast empire, which we will not be able to defend from Europe against a large, formidable, power established in that continent and bordering that country.

The count of Aranda was impressively politcally savvy, but I think that he could not have been the only one to see this coming.

Source:

Aranda, conde de (1783), Memoria secreta presentada al Rey de España por el Conde de Aranda, sobre la independencia de las colonias inglesas en América, despues de haber firmado el Tratado de París de 1783, manuscript in the BNE, reference MSS/12966/33. Transcription from

Zárate, Julio (1884), México a través de los siglos, volume III, Barcelona: Espasa y Compañía. Apéndice, document n. 2, pp. 757-8.