The one important thing is that if you are claiming any bonus or promotion then it should be from the official account and legitimate site otherwise the hackers might try to scam you with these links so you should be careful while looking at these matters.
In short, you should be aware that there are phishing attempts which may steal your username and password by asking you to click on links. If you receive any email about promotions, then check if it comes from the legit gambling site source.
1 device is used for logging in your account on any platforms you shouldn't use this on clicking anything you don't know especially links coming from unknown source. Then the other device is for use for browsing with no account attached nor any important information saved for this you can be safe for the malwares this is just additional security measure on all of your account.
The more devices you have and more security measure you can take, the better it is for you. These days the hackers will exploit every loophole and it is upon us to protect our online gambling accounts.