Emerging-market bond investors expecting a broad rally from any US-Iran peace deal may be in for a disappointment, as money managers see sticky inflation and fiscal concerns keeping long-term yields elevated.

While fading geopolitical risks should bring relief for developing-market assets by potentially driving oil prices lower, strategists including those at Goldman Sachs Group Inc. expect the gains to be concentrated at the front end of yield curves. Amid such expectations, global funds including Fidelity International and William Blair Investment Management are bearish on long-term EM debt.