Hi, I'm a complete beginner to low carbing so have only just started reading here, but I have tried milk alternatives before when I went vegan for a while. I found none really suited my taste in tea, so I went to black tea instead (start fairly weak if you want to try it). I gather black tea is known to have some benefits for the cardiovascular system (Dr Google said so!) so it's a bonus for health improvement too - the health benefits only come with black tea though, not with milk in. I had to work at it but I do prefer it without milk now.
Of the milk alternatives soya tasted best to me but usually curdled, some other people may have suggestions as to how to prevent that though.
I have noticed that a lot of people use cream instead of milk, and I'm sure there are cream alternatives that taste good in tea and coffee as well - my experiments didn't get that far!