OP is saying the recent rise in prices has to be a bubble. I disagree. There may be one coming up in May/June, which can be named "Halving Bubble 2016". But at this point, we are still in a recovery phase from the bottom, there is no bubble yet.
Yes you are right. The recent price up surge has not witnessed any rapid raising of prices. A slow and steady price movement with reasonable volume never be categorized as bubble. Until upcoming halving we can regularly see this kind of price movements for sure.