It appears that "yes", donburi kanjō is a set phrase referring to a kind of rough-and-ready approach to finances.
If you can read Japanese, this page on Kotobank has entries from both the 日本国語大辞典【にほんこくごだいじてん】 and 大辞泉【だいじせん】. I see similar entries in my copies of 広辞苑【こうじえん】, 大辞林【だいじりん】, and 新明解【しんめいかい】
Broadly speaking, this originally refers to essentially just having a pile of money, and not bothering to record debits and credits and just dealing with things as they happen. The donburi part refers to the donburi bowl, a large bowl maybe akin to some senses of the English word "pot", into which one would put all cash, taking out what is needed to settle any bills, and just throwing more money into the pot whenever paychecks come in.
By extension, the term donburi kanjō came to refer to this kind of rough-and-ready, "eh, that's about good" way of accounting: everything is "petty cash" might be one way to look at it. 😄