Any process in which an organism activates, maintains or increases the frequency, rate or extent of the type IV pilus-dependent motility of a symbiont organism (i.e. the controlled movement of a bacterial cell which is dependent on the presence of type IV pili, and which includes social gliding motility and twitching motility). The symbiont is defined as the smaller of the organisms involved in a symbiotic interaction.
positive regulation by host of bacterial type IV pilus-dependent motility