If you see yourself bowing your head during prayer in a dream, it symbolizes your surrender and humility. This indicates that you are trying to follow divine guidance in your life and are refraining from pride. Bowing your head while praying signifies your effort to adhere to God's instructions in various aspects of life.
From Imam Muhammad Ibn Seerin's Dictionary of Dreams According to Islamic Inner Traditions â entry "Rukii'" (page 368) â resolved via the equivalent "Bowing in prayers" entry.
Seeing oneself bowing to God Almighty in prayers in a dream means submission to His will, abstaining from arrogance and establishing God's rules in one's life. Bowing in prayers also means fulfilling one's aspirations in this world and quickly triumphing over one's enemy. If one sees himself standing in prayers, but remains standing without bowing until the prescribed time elapses in a dream, it means that he does not pay his due alms. Bowing in prayers in a dream also means ajob for someone who needs it most. Bowing in a dream also means longevity. If a woman sees herself bowing before God Almighty in prayers in a dream, it means repentance and exalting her name by protecting her chastity. (Also see Prayers)
Note: Islamic dream interpretation depends on the dreamer's circumstances and state. This is a general guide drawn directly from the source book.