A couple making 90k, after deductions, would likely be in the 15% tax bracket, and paying an effective federal tax rate of 7.5% or lower. This is probably true of most middle/upper middle class households.
At the lower income level, UBI would go more toward basic necessities. So it will be a plus for them. Will UBI be a gain or a loss for middle/upper middle class households? Honestly, I am not sure. It will likely depend on what happened to the tax bracket.
In your example UBI comes with a 10% increase at the 25% tax bracket. What about the 15% tax bracket? A 10% increase also? How about the 28% and 33% brackets? Would the 10% increase apply to long-term capital gain? How about short-term capital gain? How about people older than 65? Do they have to pay the tax increase on their SS and the money that they draw from their retirement funds?