I’m sorry, but while the simple answer to your question is "No, it doesn't", in fact there are so many ways to answer your question about δέκα and δεκάς. [Please ignore those that are not relevant to what you had in mind (perhaps all of them)];
If your question is about the origin of the English word “decade” and you wanted to translate that idea into Greek, then perhaps the words δεκαετία ἡ [δekaetía] χρονικὸν διάστημα ἤτοι (“viz.” not “whether”) περίοδος δέκα ἐτῶν. or the word δεκαετής -ές [δekaetís] ἐπίθετον ὃ διαρκεῖ δέκα ἔτη.(Using ἤτοι here in this way implies that in regard to Romans 6:16 I think that the dictionary meaning “whether” is a convenient rendering for the sake of translating that verse into English, rather than the “real” meaning of the word. I think that ἤτοι is a synonym of δηλαδὴ (i.e.) rather than the natural antecedent of ἢ).
If your question is about tithing, I suggest you look further down the page at the word δέκατος. (Perhaps you are forming the adjective in a non-standard way).
If your question is a general one about the Greek language, then the meaning for the word δεκάς ἡ [δekáδa] 1. σύνολον ἀποτελεῖται ἀπὸ δέκα μονάδων: 2. ὁμάς δέκα ὁμοίων προσώπων ἢ πραγμάτων. is a subset of the meanings for the word δέκα [δéka] 1. ἐπίθετον ὃ δηλοῖ ἓν σύνολον ἐκ δέκα (10) μονάδων. 2. (ὡς οὐσιαστικὸν.) τὸ δέκα: ὁ ἀριθμὸς καὶ τὸ γεγραμμένον σύμβολόν αὐτοῦ (δηλαδὴ τὸ<< ι’>> ἢ 10). Here, the main difference between the two is that δεκάς only functions as a noun (an abstract sor of one), whereas δέκα can function as either a noun or an adjective. I would expect to find δεκάς in philosophical texts not in texts written in a popular style.
If you are asking whether the NT has proto-Gnostic influences, then I think that the fact that we don’t see these –ά(δ)ς forms for numerals is slightly significant. They are more frequent in Gnostic or other cosmogonic / theogonic texts. If you are asking a question like this, then perhaps you could ask about (οἱ) δώδεκα which are never referred to as ἡ δωδεκάς. The apostles were real people and individuals. The NT is written in a more bare-knuckles style of Greek than the abstract philosophical style of texts where the –ά(δ)ς forms are likely to occur.
"I’ll bet you can’t tell me what it smells like in the Sistine Chapel." (Good Will Hunting - 1997)