I cannot recall anything where it implicitly states that they are treated differently because they were created by Aulë
They are treated differently (and held in contempt) by elves due in part to their actions during the wars with Morgoth, stealing the treasure of Doriath including the Nauglamír (with Silmaril) and killing Thingol:
Thingol, gazing upon Nauglamír, thought to have it remade to hold the Silmaril of Fëanor, with which he had become obsessed, as had its previous keepers.
Dwarves from Nogrod still stayed on occasion in Doriath to assist with metal- and stonework, and Thingol revealed his desire to them, and looking upon the Silmaril, they coveted it also, but consented to the task.
When it was finished, Thingol sought to take it back from them, but they withheld it from him on the pretext that Nauglamír had been made by their fathers and given as a gift to Finrod Felagund, who was dead, but Thingol saw through their claims to their lust for the Silmaril and ordered them to leave his halls.
The Dwarves rose up against him and killed him, taking Nauglamír and the Silmaril.
The Silmarillion - "Of the Ruin of Doriath"
This hatred is shown by:
Celeborn had no liking for Dwarves of any race (as he showed to Gimli in Lothlorien), and never forgave them for their part in the destruction of Doriath.
Unfinished Tales - "Of Galadriel and Celeborn"
Celeborn being a kinsman of Thingol
and:
In ancient days [the elves] had had wars with some of the dwarves, whom they accused of stealing their treasure.
It is only fair to say that the dwarves gave a different account, and said that they only took what was their due, for the elf-king had bargained with them to shape his raw gold and silver, and had afterwards refused to give them their pay.
The Hobbit - "Chapter VIII: Flies and Spiders"
The animosity between them was prophesied by Ilúvatar:
But when the time comes I will awaken them, and they shall be to thee as children; and often strife will arise between thine and mine, the children of my adoption and the children of my choice.
The Silmarillion - "Of Aulë and Yavanna"
Also, after Aulë tells Yavanna of the Dwarves, she speaks almost prophetically of some reasons for this strife.
Yet because thou hidest this thought from me until its achievement, thy children will have little love for the things of my love.
They will love first the things made by their own hands, as doth their father. They will delve in the earth, and the things that grow and live upon the earth they will not heed. Many a tree shall feel the bite of their iron without pity.
The Silmarillion - "Of Aulë and Yavanna"
So whilst the strife here is caused by the actions of the dwarves, and not because they are adopted children of Ilúvatar, which led the elves to bear them ill because of this. However it was always destined to occur, it was just the form it would manifest in that was not yet known.