Both the Bear and Gus are introduced during season two...Vince Gilligan mentioned in the Season 4 DVD extras that Gus' death had been planned "for a long time" (Or words to that effect) So it's entirely possible...
"The teddy bear eyeball that Walt found in his swimming pool is symbolic. It's very, very symbolic. However, I'm not sure I can tell you with 100% certainty of what the symbolism is, what it represents...On the face of it, when we were coming up with that eye as an image, it probably, represented some form of the eye of the universe, the eye of god, the eye of morality, I suppose judging Walter White...And so symbolism like the eyeball, I'm not sure what it means to me completely but I'm always interested in hearing what it means to viewers of the show. I guess if you're going to hold my feet to the fire, what it means to me is the eye of God on Walt. If not necessarily judging him, nonetheless watching him, keeping tabs on him. And then the question: If that is what the symbolism stands for, then why does Walt keep that eye? Why does he keep it in his drawer versus discarding it?"
―Vince Gilligan
The bear is also present in the background, as late as "Rabid Dog" (Season 5B) Whilst the last person seen with the missing eye is Skyler in "Box Cutter"...My view is that it's a sign of the "Gus Fring" ruthlessness that consumed Walt, and we see it start to consume Skyler as well after she finds it... (Starts to become involved more heavily in Walt's money laundering)