Wines typically vary between 500 calories per bottle and 1500 calories per bottle depending on the type of wine. There are the initial 'present' calories and then the fact that alcohol metabolizes as sugar (big reason why recovering alcoholics crave sweets).
Considering that there are 4 glasses of wine per most bottles = 125 - 375 calories per glass.
There's 100-300 calories on average per bottle of beer.
The reason why they're "similar" is the alcohol content. Beer INITIALLY has more calories than wine, but Wine tends to have a much higher alcohol content than beer, so the calories increase. (because of the alcohol metabolizing).
People tend to drink less wine in one sitting than beer (higher alchol usually means drinking less), so people typically consume fewer calories. (ditto hard alcohol).
The "fattening" aspect, to either, however. Tends to be LESS the calories involved, and more the increasing size of the liver. Add in that drinking, for most people, is a pretty sedentary AND that people tend to eat less, means that their bodies typically start storing more fat as a response to nutritional deficiency/ exercise deficiency.
People are notorious for losing a lot of weight when they quit drinking beer for a month or two, because they're cutting out ###-###-#### calories out of their day, and their liver shrinks in response to fewer toxins to filter out, AND they're typically bored / find something else to fill their time (aka become slightly to massively more active). "Beer Bellies" (also found in people who drink a lot of wine) have nothing to do with FAT, but are a person's LIVER. You can see a very skinny man with a HUGE belly (beer belly), and ya know... you're looking at his liver.