Jesus is the target of the Abraham covenant. He fulfilled it.
“It is not as though the word of God had failed. For not all those who are descended from Israel are truly Israel,nor are all the children Abraham’s true descendants; rather “through Isaac will your descendants be counted.”This means it is not the children of the flesh who are the children of God; rather, the children of promise are counted as descendants.” (Romans 9:6–8) (NET)
“Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.” (Galatians 3:16) (KJV 1900)
“And if ye be Christ’s, then are ye Abraham’s seed, and heirs according to the promise.” (Galatians 3:29) (KJV 1900)
Well, yes, Jesus is the target of the Abrahamic Covenant, just like Jesus is the 'target' of every covenant made. Just like Jesus is the target of the entire Bible. Just like Jesus is the target of God's whole creation.
If you notice, both Jesus is spoken of as the 'Seed', and the believers are spoken of as Abrahams seed. Compare the two verses you gave in (Gal.3:16) and (3:29).
All is based on Jesus Christ, of course, who is The Seed. But then Christ the Seed, has produced also the believing Israel, and the believing Church.
(Gal. 3:7) "Know ye therefore that they which are of faith, the same are the children of Abraham."
Stranger