The first expression is broad; the second is deliberately selective. In the partitive analysis, the particular blessings described are not claimed to exhaust every known blessing. Rather, the context selects blessings of special rhetorical importance.
The coordination in «وَجَنَّاتٍ وَعُيُونٍ» joins items within the detailed enumeration. It is not the same as adding wāw between the two principal clauses. Faṣl and waṣl must always be evaluated at the actual level of clauses being compared.