That's sort of true, but I'm not sure if that the inflation effects are truly a "tax on wealth". Inflation is a tax on everybody, holding a wide range of assets in that sense. Also because it's driven by inflation, those proceeds to the government are also just growth of proceeds needed to buffer against inflation in the goods that government purchases.

Edit: Thinking about it a bit more. Inflation would also tend to drive up the numerical profits of companies, which will tend to buffer a stock price for example. So I'm not sure how this inflation independently contributes much of a specific tax on the wealth.