I can't see any reason why a Semi Synthetic oil would not be a good choice in a GTV regardless of how the car is driven (spirited, odd track day etc). Aas long as the car is warmed up correctly and has regular interval oil changes then the engine will be absolutely fine.
As already mentioned, fully synthetic oils are superior to semi synthetic oils in almost every aspect (especially the esther based ones). Using fully synthetic will also lubricate to a good enough standard but I really think you'd be hard pushed to notice a difference in engine wear over say 50k miles between the two. If the oil was going into a highly stressed and highly tuned engine then I'd always go for a fully synthetic, however neither TS or 3.0 V6 are highly stressed engines so will be fine as long as they are lubricated with decent oil at regular intervals.