Lopsided training schedules

dude if it is working great.

Haven't a clue about the spinning though.

I don't think so. I did a lot of spinning early season this year, my schedule was tight and it worked for me timing wise. 2 hour in the real saddle is I think a lot more valuable time than an hour on a spin bike. in the saddle you are using more muscles (all of your balance and core muscles), you speed up and slow down more than you realize. I find that hour spin classes are really 50mins with fluff either side. Ya you go hard for that time, but it's not specific Tri bike training. If you do a focused 2 hrs on the bike that's good training time. Just don't slack on the 2hr rides, make each workout have a purpose.

I will say that in my experience, spinning help me to keep my bike fitness (or slow down losing it more likely). Once I was able to get outside and riding again this year, my biking legs came back a lot faster than I would have expected. Pretty sure the 3hrs or so a week I was doing spinning during the cold and wet months helped with that. I was also trying to do a very hard CompuTrainer session a week too, but was consistent with the spin classes.

My training schedule is way lopsided too but it has to fit with work, kids, squad times etc.  This isn't perfect but it's real life, like you I would really prefer to balance it differently but I make my schedule fit around my life, not the other way around.  Do what you can, when you can and don't worry about it.  Spinning is great, a "real" bike ride is always better IMHO but it's better than nothing and I always really enjoy the class.