Yes, PhoneBot is absolutely safe for several reasons:
PhoneBot doesn't ask you for your social credentials. It doesn't store any passwords or any other personal details. So even if PhoneBot system would be pirated by criminals hackers, they wouldn't find any sensitive information.
PhoneBot is not a server running on your computer. It is a simple program that takes control of your smartphone to automate some tasks. In other words, PhoneBot doesn't open any door for potential attacks.