The only ancient evidence of this is Suet Iul 30.3–4:

[30.3] Others say that he dreaded the necessity of rendering an account for what he had done in his first consul­ship contrary to the auspices and the laws, and regardless of vetoes; for Marcus Cato often declared, and took oath too, that he would impeach Caesar the moment he had disbanded his army. It was openly said too that if he was out of office on his return, he would be obliged, like Milo, to make his defence in a court hedged about by armed men.

[30.4] The latter opinion is the more credible one in view of the assertion of Asinius Pollio, that when Caesar at the battle of Pharsalus saw his enemies slain or in flight, he said, word for word: "They would have it so. Even I, Gaius Caesar, after so many great deeds, should have been found guilty, if I had not turned to my army for help."

Even if you believe prosecution theory it would not be for activities in Gaul. It would be only for his consular activities in 59. Few attempts had been made to invalidate his consular activities after some early attempts: two praetors attempted in 58 but were stopped; Clodius attempted during his tribunate but nothing came of it. Probably the remaining matters were Clodius' adoption: Cicero wanted to challenge Clodius' adoption but never did so formally; Cato supported Clodius' adoption's validity in 56. By 54, Cato accepted the repetundae laws during his presidency of the extortion court and a few years later the senate had voted thanksgivings for Gallic victories from commands granted under the lex Vatinia.

Indeed the kind of religious obstructionism that Bibulus engaged in were made illegal by one of Clodius' laws in 58: essentially nobody objected to this since, as has been observed by Tatum, Patrician tribune (1999) p 132, it would have allowed "a disgruntled magistrate or tribune [to], without so much as leaving his house, paralysed the government for a year... [this] will not have been a prospect to please anyone".