I am the mom of a refluxer as well. What medication is she on? Most of them only stop or block the production of acid so that it doesn't cause damage to her esophagus when she spits up. The common misconception is that the medication makes the reflux go away....it does not. But if she doesn't seem bothered, in pain, crying etc then the meds are most likely working properly for her so its not damaging her. My son is 27 months old and will spit up 1-2 times a month now (we have also weaned him off the meds a few months ago) but at your daughters age it was ALL day every day. I know the laundry seems endless, but it does get better. The majority of babies with reflux will outgrow it by the time they reach a year. There are those few that have it continue long after that but those are usually accompanied with other medical issues (like my son) that can complicate the reflux.
If the spitting up has NOT increased with the change in formula or food then I would not think it is an allergy issue. I found with my son doing smaller but more frequent feedings helped a little and be sure she is upright or at a 35 degree angle for 30-45 minutes after eating/drinking.
You also mentioned that some food from hours ago came up.....this can be a sign of delayed gastric emptying (lots of reflux kids have this ranging from very minor to severe). Some research believes that the medications such as Prevacid etc to treat the acid production for reflux can cause delayed emptying. Essentially the theory is that we all use the acid in our stomachs to digest and move food into the intestines. If you decrease that acid in the stomach then the food is slower to digest and move out of the stomach. This can mean that although it may have been a few hours and it is time for baby to eat again, if they spit up some of the new feeding, the older stuff can be right there still as well. If this is a big issue and seems to occur often there are a couple of medication choices that her doctor can prescribe to assist her digestive system in moving food out of the stomach quicker.
Sorry this is so long and I hope it isn't too much information. If you ever have more questions or want to talk PM me. I would love to help!