Is it obligatory to purify the bedding and personal items (such as a mobile phone and wallet) after urine impurity has transferred to them, knowing that this was due to deliberate negligence in the past?

You must sincerely repent from being lax in matters of purity. The default state of things is purity, and nothing is judged to be impure except with certainty and evidence. Therefore, adhere to this principle regarding your bedding and your home, and do not open the door to misgivings upon yourself.