Hi,
My scenario is similar in that I am totally in the Vanguard Family and have 3 types of accounts:
1. Regular Brokerage (non-IRA).
2. 401K Rollover (my employer discontinued their 401k a while back...).
3. Roth IRA
I have 3 opinions regarding your allocations:
1. At your age, personally, I would NOT own any bonds for retirement purposes, unless you have a low risk tolerance and would panic during a big downturn (how did you handle 2007-2010?). Since you are target 2055, I am guessing you are pretty young. I would just "ride the rollercoaster" as long as you are at least 15 years from retirement/FIRE. Target Date funds allocate bonds based on your age. I would just "put the pedal to the metal" for now.
2. While people on this board rave about VTMSAX, it is fairly concentrated in large cap stocks, lacking optimal diversification (check out this podcast:
http://paulmerriman.com/10-reasons-dont-like-vanguards-total-stock-market-index-fund/). I suggest you follow Paul's "Ultimate Buy and Hold":
http://paulmerriman.com/mutual-funds/ (click on Vanguard) and do 100% stocks if you can stomach it. Follow the allocations across all accounts (as if they are "one"). This will likely strike you as "too much work" to rebalance...you only need to do it ONCE PER YEAR!
3. If you want to diversify with REIT's, you probably should do so in retirement accounts, since REIT's are dividend heavy.