As long as you are getting a good flow up to the rocker arm you are good. The other side of the "oiler" (as I call it) should be coming from the oiler and pointing down to the head and should be "squirting" oil onto the head itself. So a little leakage around the tube from the head flowing towards the rocker arms would be okay. Also, the tube coming up through the head comes right out of a galley from the oil pump, so as long as the oil pressure is good and you are getting a good flow through the rockers and onto the head, no big deal.
However, this is be careful territory since (as I'm finding) the OEM and replacement oilers are hard to come by.
