Hi Ernie, and welcome. You need to post to a newer thread to be sure people will see your posts and answer questions. This thread was last seen in 2014, I just happened to bump into it. The "Summer 2016 . . " thread is the most current and active here at the moment. Think we need a new thread for winter, don't we.
As far as your allamanda goes, we've sure not had any weather cold enough to burn it yet here. How far north are you? The cooler nights can sure slow things down though.
The other thing that can cause tip burn on the leaves is too much fertilizer - when the plants slow down in winter either due to cooler weather or less sunlight (short days, lower sun) they really don't need any fertilizer.
