Exponential growth can continue in virtual realities as the physical reality maxes out.
But information doesn't need to be rationed in that way: what happens if people join an open source virtual reality instead, where consumption is unlimited and production is voluntary? Nothing in this world would be part of the economy as economists measure it.
Shuffling bits around takes energy; if your virtual reality services grow exponentially and energy production doesn't, then the price of energy must also increase exponentially or else one of your VR companies could buy all the energy and shut down the competition.
Energy production (and computation) are limited by the capacity of the earth to vent heat into space at a reasonable surface temperature.
So unless you allow for an exponentially expanding real-world physical economy, you can't have an exponentially growing virtual economy.