Here's what CE says about St. Robert's understanding of St. Augustine:

Quote

It is clear that Bellarmine found the situation embarrassing, being unwilling, as he was, to admit that St. Thomas and the Schoolmen generally were in conflict with what St. Augustine and other Fathers considered to be de fide, and what the Council of Florence seemed to have taught definitively. Hence he names Catharinus and some others as revivers of the Pelagian error, as though their teaching differed in substance from the general teaching of the School, and tries in a milder way to refute what he concedes to be the view of St. Thomas (op. cit., vi-vii). He himself adopts a view which is substantially that of Abelard mentioned above; but he is obliged to do violence to the text of St. Augustine and other Fathers in his attempt to explain them in conformity with this view, and to contradict the principle he elsewhere insists upon that "original sin does not destroy the natural but only the supernatural order." (op. cit., iv).

The notion of predestination comprises two essential elements: God's infallible foreknowledge ( prœscientia ), and His immutable decree ( decretum ) of eternal happiness. The theologian who, following in the footsteps of the Pelagians, would limit the Divine activity to the eternal foreknowledge and exclude the Divine will, would at once fall into Deism, which asserts that God, having created all things, leaves man and the universe to their fate and refrains from all active interference. Though the purely natural gifts of God, as descent from pious parents, good education, and the providential guidance of man's external career, may also be called effects of predestination, still, strictly speaking, the term implies only those blessings which lie in the supernatural sphere, as sanctifying grace, all actual graces, and among them in particular those which carry with them final perseverance and a happy death. Since in reality only those reach heaven who die in the state of justification or sanctifying grace , all these and only these are numbered among the predestined, strictly so called. From this it follows that we must reckon among them also all children who die in baptismal grace, as well as those adults who, after a life stained with sin, are converted on their death-beds. The same is true of the numerous predestined who, though outside the pale of the true Church of Christ, yet depart from this life in the state of grace as catechumens, Protestants in good faith, schismatics, Jєωs, Mahommedans, and pagans. Those fortunate Catholics who at the close of a long life are still clothed in their baptismal innocence, or who after many relapses into mortal sin persevere till the end, are not indeed predestined more firmly, but are more signally favoured than the last-named categories of persons.



Predestination - Encyclopedia Volume - Catholic Encyclopedia - Catholic Online

Read St. Robert's opinion on the issue of this thread again - Chapter VI in the excerpt contained in the article on pp. 16-17. I don't see St. Robert's opinion departing from Augustine at all, whom he quotes at length in the Chapter, and not by way of distinction, but agreement. He doesn't quote Abelard at all. 

I question whether St. Robert agreed with Abelard. From what I read, in St. Robert's own expression of his view, he "adopts a view which is substantially that of" Augustine. 

The CE is really only useful as confirmation of another source of support, of a reliable independent witness. One can also use it to support an argument in the sense that "I can't be out of my mind or heretical in this, cf. the CE, which agrees with me." But it's limited as authority to those senses in my view. 

I say if one agrees with the CE one can't be "heretical" . . . but that's only because I don't make that call. I would call the above excerpt . . . heretical. 

This is relevant to Augustine's view on salvation of infants, although not directly to their punishment.

Not only did St. Augustine believe the sacrament of baptism was necessary for all, he believed that every single person, including infants (!) must receive the Eucharist.





This gives us an insight into Augustine's mind - he does not shy away from harsh doctrine. It would hardly be inconsistent for him to consign infants to positive punishments.

John 11:25-25

25 Jesus said to her: I am the resurrection and the life: he that believeth in me, although he be dead, shall live:

26 And every one that liveth, and believeth in me, shall not die for ever.

No, it is not related to their punishment, which isn't mentioned.