While the fuel price hike is some distance away..weakening dollar will certainly help keep the under recoveries in check. Crude Oil prices can not sustain much above where they are at today ($75-$85) in the short to medium term....so the threat of huge under-recoveries seems not so significant.
I too believe the results will be stronger in quarters to come and hence we should see the stock performing well.
Bonus in itself should not have a significant impact on price and the Ex bonus price should ideally be around half of what it is trading at cum-bonus(300-350).