If you buy the cheaper version of hot dogs then yes they are the same meat as bologna and they taste the same.
The cheaper hot dogs are not really hot dogs as in they are not really beef hot dogs like other higher priced beef hot dogs are.
The cheaper hot dogs are made from chicken, pork and sometimes beef mixed together and are made from leftover meats from preparing other meats.
Just like bologna can be made from chicken, pork and sometimes beef remnants the hot dogs are too.
If you buy the higher priced hot dogs that are beef hot dogs then those would not be the same as bologna.
For example bratwursts hot dogs are not the same as bologna and use a different meat entirely.