Yes. You can open several Credit Lines and keep them open at the same time, for example one in USDT and one in USDC. Each one starts at 100 USDT or USDC.
Each Credit Line is separate. It has its own collateral, LTV and interest rate, and you repay and close each one on its own.
To open another one, go to Borrow and tap Open Credit Line. See How do I open a Credit Line?