Yes, you can log in to your Touch 'n Go eWallet account using another device as long as it is not jailbroken/rooted.
Below are the articles that may be useful for you :
If I log in to my Touch ‘n Go eWallet account using a jailbroken / rooted device, will my Touch ‘n Go eWallet account be suspended?
Why is the Touch ‘n Go eWallet app not supported on jailbroken / rooted devices?
Can I continue enjoying the RFID and/or the “TNG Card” feature?