A couple things Ob. I was aware of your dive into Wellesley, but was surprised about your dive into the intermediate term bond fund.
The data in your OP seems to be based on the Wellesley growth of $10,000 chart on their website and comparing April 30 to July 31. IIRC you made you investment in Wellesley in early March so if your are going to assess your investment performance based on that graph you should probably look at Feb 28 ($10,490) compared to Jul 31 ($10,788). Alternatively, you could compare the share price(s) you bought at to the current share price but that would be somewhat too simple since you have received a couple dividends since March. Based on the timing of the post when you bought Wellesley, I think you may be up. The best way to assess your performance is to (if you use Quicken) look at a Investment Performance Report for that holding since it will look at the specific day(s) you invested and any dividends were reinvested and the ending value. Or if you don't use Quicken you can log on to VG and go to Personal Performance under the My Accounts tab and look at the Select specific holdings choice on that screen.
On the bond fund, intermediate term bonds have been taking a beating lately and you may have seen several threads where some people are concerned about the near term outlook for bonds given the widely expected increase in interest rates (which cause the value of bonds to decline) and that is what is driving the decline in that fund. That fund has a duration of 6.6, which means that for each 1% increase in interest rates that one would expect that fund to decline in value 6.6%. If the economy continues to improve and interest rates increase then one would expect that and other bond funds to decline in value and gradually recover over the long run as maturing bonds are reinvested by the funds at those higher interest rates. So if your time horizon for this investment is long (say 10 years or more) then you should come out fine in the long run.
As you may appreciate having been around here for a long time, many of us hold bonds not because we love bonds or the income of bonds, but to add stability and diversification to our overall portfolios. IOW, for me for example, as interest rates rise I expect my bond returns to be negative in the short term and very modest (2-3%) in the long term but assuming the cause of the interest rate rise is an improving economy I expect my equities to do very well and the 40% of bonds that I hold add stability and diversification to my overall portfolio. To be candid, since you don't hold any stocks (other than inside Wellesley) so you won't gain the diversification benefits of bonds, I would not see bonds as being a good investment for you in the near term.
If I was investing only for income, I would not be keen on bond funds right now due to the interest rate risk, but I would favor individual bonds or target date bond funds. Over the past 6 months, I have moved a significant part of my bond portfolio to target date bond funds that mature in 2019 and 2020 as a substitute for CDs.