Pretty unlikely to be a problem. I find grocery bags, wads of plastic hay twine, even pieces of baleage bags in cattle's rumens all the time - just sitting there, not causing any problem - the animal died of totally unrelated issues. Sure, other respondents have detailed their individual cases, and I'm not saying they don't ever happen, but in 35 years of veterinary practice and diagnostic pathology, I've NEVER seen a cow or calf that had an issue from ingesting non-digestible stuff like a plastic bag.
Back when I was in college, we had a rejected calf that we raised on a bottle - he would not stay in the pasture - went up and down the sides of the highway frontage eating every piece of trash that anyone threw out of their car - McDonalds bags(paper, in those days) those styrofoam Big Mac containers(this was back in the '70s), etc. didn't matter - he was gonna eat it. Never caused him a minute's problem; but the day he chewed up one leg on each of 4 brand new pair of Levi's that I'd washed and hung on the line, was the last straw - it was off to the processor for him.