If my opponent gusts a Sprite and I have Viktor Leader out, does it spawn a Recruit token at base?

No, Viktor, Leader will not spawn a recruit token at your base if a Sprite is returned to your hand by Gust.

According to the RiftJudge FAQ #738:

• Ruling: "The sprite does not count as dying for Viktor Leader's effect. The sprite token is returned to hand and then ceases to exist, but this is not considered dying by a regular method."

Sequence:

1. Your opponent plays Gust targeting your Sprite.
2. Gust resolves and returns the Sprite token to your hand.
3. Upon reaching your hand, the token ceases to exist.
4. Because the token did not "die" (a regular method for a unit to leave the board and enter the trash), Viktor, Leader's triggered ability does not trigger.