Purity: Validity of Tayammum for Other Acts
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 714:
If someone’s duty is to perform tayammum and he performs it for some act, then as long as his tayammum and the legitimate excuse remain valid, he can perform those acts that must be performed with wuḍūʾ or ghusl. However, if his legitimate excuse was a shortage of time, or despite having water he performed tayammum for ṣalāt al‑mayyit or sleeping, then with that tayammum he can perform only those acts for which he performed tayammum.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)