So, when you say these things are apostolic, you can't really make the connection.
If by that you mean the writing of an Apostle including asking a martyr to pray for us?
No, but if the Church is doing that in the regular worship and it is not ok for them to be doing it, isn't it reasonable to conclude the Apostles would have said something about it?
It is not like some early Father suddenly came up with the notion, it is in the detailed liturgy. The form of which apparently is unchanged from the first century, and a form which includes a section invoking such prayer. Yet no Apostle speaking against it.
As far as apostles speaking out, when they had two perfect examples in James son of Zebedee and Stephen martyred, there's no mention at all about praying to them.
Except for the Revelation of John, which interestingly also includes these prayers in it's form (elders with prayers in urns) we do not have an Apostle giving us the liturgy.
We do have evidence that the martyrs were included in this liturgy and early Fathers speaking of it from the 1st century and non-Catholic theologians agreeing at least that much was so. Circumstantial in regards to the Apostles? Well sure if you discard what John says and how some people view his vision.
But this also begs the question, who were the first ones invoked? Mary, Peter, or a specific angel, or was it a general thing?
As Mary and Peter outlive the first martyrs of note and this practice is apparently pervasive by the end of the first century I doubt it was them.
In the first century Hermas is shown doing it with angels. The liturgy includes asking both, so including all heavenly hosts. So I would think it would have occurred to them to include all the hosts in Heaven when they included it in their regular worship. And given Apostles still living I cannot imagine a liturgy being used that did not meet their approval.
So to me it does not really matter if a particular saint is invoked first, the fact they were doing it and the Apostles endorsed it s enough.