Quite right, Jesus didn't say, "I am Theos." However, He certainly said things that cause even His enemies to realise that He was claiming equality with God:
(Joh 5:18 NKJV) Therefore the Jews sought all the more to kill Him, because He not only broke the Sabbath, but also said that God was His Father, making Himself equal with God.
He also said:
(Joh 10:30) " I and My Father are one."
(Joh 14:9) Jesus said to him, "Have I been with you so long, and yet you have not known Me, Philip? He who has seen Me has seen the Father; so how can you say, 'Show us the Father'?
So the meaning (that Jesus is God) is there.
The same cannot be said of what the vow was that Paul took at Cenchrea. It isn't said in different words. We are just pot told.