Do you have a 401(k), or are these two accounts all you have?
How much of this is for retirement and how much is for some other use? You may want to treat the two as different if some is for retirement and some isn't.
How many capital gains do you have in the taxable, and what kind are they (short or long term)?
At the very least, I'd look into using the total market instead of the S&P 500 for your domestic stock portion, especially now that the expense ratios are the same.
I'm a big believer in the
three fund portfolio and in having
at least some bonds - 10% is fine. There isn't a significant benefit to being 100% stocks versus 90% stocks 10% bonds, but there's much more volatility.
If you're going to grab some international stocks, do so in taxable, if you intend to treat all of your retirement funds as one big portfolio. I like 30% of my stocks to be in international, although admittedly it's more that I started by seeing that's what Vanguard's target date funds did, and didn't find a good reason to change that allocation.
I'd also suggest
turning off re-investment of dividends in taxable if you're going to wait for it to become long-term capital gains and then sell. Use the dividends to buy into the fund(s) you're going to transfer into anyway (which you might start with future contributions). Within the Roth IRA, you can go directly to your desired asset allocation.