Yes, you can! When the sky is clear (no calima) you can see Tenerife very clear, from several points on the island. Sometimes the hill in Galdar is mistaken for El Teide, the highest point in Spain, so it’s good to keep this in mind: if you can only see one mountain, it’s Galdar. If you can see two, the one on the right is El Teide.
The better the weather is, the more you can see of Tenerife. After all, Tenerife is only roughly 70km away from Gran Canaria.
Check some pictures below from Tenerife from different view points.